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Del Mar Photonics - Newsletter Fall 2010 - Newsletter Winter 2010

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Microstructured fiber with high-birefringence and low-noncircularity mode field

Paper 7914-87 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Alexander N. Denisov, Andrey E. Levchenko, Sergei L. Semjonov, Evgeniy M. Dianov, Fiber Optics Research Ctr. (Russian Federation)
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A new design of polarization-maintaining microstructured fiber will be presented. A solid core is surrounded by two or more concentric rings of holes of constant diameter. The distance between adjacent holes in the first ring is constant except for one or two pairs of holes, for which the spacing is increased. It is found that the fiber of such a design can demonstrate high birefringence (up to 5x10-3) and simultaneously low circular asymmetry of the mode shape. A set of experimental samples was fabricated. The measured values of birefringence were in excellent agreement with the calculated ones.

100 kW peak power, single polarization, high-brightness nanosecond lasers based on 3C optical fiber

Paper 7914-29 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 11:40 AM – 12:00 PM

Author(s): Michelle L. Stock, Chi-Hung Liu, Andrey Kuznetsov, Gaston E. Tudury, Arbor Photonics, Inc. (United States); Almantas Galvanauskas, Univ. of Michigan (United States); Thomas S. Sosnowski, Arbor Photonics, Inc. (United States)
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Double-clad fiber amplifiers with 100 kW peak power in 10 nanosecond pulses have been constructed using a new fiber structure called 3C (Chirally-Coupled Core) optical fiber. These amplifiers produce single-mode output with M2 < 1.1. Recent advances in 3C fiber design also enable high fidelity, single polarization output. Polarization extinction of 20 dB is reported from a 35 µm core, 3C fiber amplifier. Mode quality and polarization are maintained in active and passive fibers, allowing construction of robust 3C fiber components. Polarization and mode quality are insensitive to temperature and mechanical perturbations even at average output powers >50 W.

Modal analysis of beams emerging from a multi-core fiber using computer-generated holograms

Paper 7914-88 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Christian Schulze, Oliver A. Schmidt, Daniel Flamm, Michael R. Duparré, Friedrich-Schiller-Univ. Jena (Germany); Siegmund Schröter, Institut für Photonische Technologien e.V. (Germany)
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We investigate the beam emerging from a 3m-long passive large mode area multi-core fiber (MCF) at two different wavelengths to demonstrate the analysis of differently complex mode mixtures. Our method uses a computer generated hologram to modally decompose the beam exiting the fiber end facet. At 1064 nm the MCF is measured to be single-mode whereas at 633 nm 10 modes can exist. At 633 nm excitation of distinct mode mixtures is done by changing the input coupling situation enabled by a nano-positioning device. Furthermore it is demonstrated how bending of the fiber alters the modal spectrum.

Q-switched fiber lasers

Paper 7912-35 of Conference 7912
Date: Tuesday, 25 January 2011
Time: 2:50 PM – 3:10 PM

Author(s): Scott Christensen, Nufern (United States)
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Actively Q-switched ytterbium-doped tapered fiber laser

Paper 7914-69 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Valery Filippov, Juho Kerttula, Tampere Univ. of Technology (Finland); Yuri K. Chamorovskii, Konstantin Golant, Institute of Radio Engineering and Electronics (Russian Federation); Oleg G. Okhotnikov, Tampere Univ. of Technology (Finland)
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We report an actively Q-switched double-clad ytterbium doped tapered fiber laser. The large mode area and intrinsic amplified spontaneous emission suppression mechanisms allowed to generate of 2 mJ, sub-100-ns pulses at extremely low (up to single-shot) repetition rates with near diffracted limited beam quality.

Generation of 30 fs pulses at 670 nm using a frequency-doubled fiber laser system and a photonic-crystal fiber with two zero-dispersion wavelengths

Paper 7914-80 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Robert Herda, Tobias Junggeburth, TOPTICA Photonics AG (Germany); Kim Per Hansen, NKT Photonics A/S (Denmark); Patrick Leisching, TOPTICA Photonics AG (Germany)
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The frequency-doubled radiation of an Erbium-doped fiber laser is used for supercontinuum generation in a small-core microstructured fiber with two zero-dispersion wavelengths. Average powers up to 49 mW are launched into the microstructured fiber. The generated supercontinuum shows a short-wavelength peak centered around 670 nm and a long-wavelength peak centered around 1100 nm. More than 35 mW is contained in the low wavelength peak. We use the anomalous dispersion of a SF10 prism compressor to compress the low wavelength peak of the spectrum. The compressed pulse has a central wavelength of 670 nm and a duration of 30 fs.

S2 imaging of LMA photonic crystal fiber amplifiers

Paper 7914-84 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Marko Laurila, Technical Univ. of Denmark (Denmark); Thomas T. Alkeskjold, Jes Broeng, NKT Photonics A/S (Denmark); Jesper Laegsgaard, Technical Univ. of Denmark (Denmark)
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Modal characterization using spatial and spectral resolved imaging (S2) has emerged as a novel method for characterizing modal content of LMA fibers without the need for bending. In this paper, S2 imaging is applied to different ytterbium-doped LMA PCFs and step-index fiber amplifiers and the potential limitations of S2 imaging is addressed. The single-mode performance of LMA PCFs is evaluated by measuring the higher-order mode content for various launch and coiling configurations. Cross-sectional tilt is also addressed.

A novel hybrid three-band transport system based on a DFB LD with multi-wavelength output characteristic

Paper 7959-9 of Conference 7959
Date: Wednesday, 26 January 2011
Time: 2:50 PM – 3:20 PM

Author(s): Hai-Han Lu, Peng-Chun Peng, Hsiang-Chun Peng, Chung-Yi Li, Heng-Sheng Su, National Taipei Univ. of Technology (Taiwan)
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A potentially cost-effective radio-over-fiber (ROF)/fiber-to-the-X (FTTX)/CATV hybrid three-band transport system based on direct modulation of a distributed feedback laser diode (DFB LD) with multi-wavelength output characteristic is proposed and experimentally demonstrated. Directly modulated radio-frequency (RF) (1.25Gbps/6GHz), externally remodulated baseband (BB) (622 Mbps), and externally remodulated CATV (channels 2-78) signals are successfully transmitted simultaneously. Over an 80-km single-mode fiber (SMF) transmission, low bit error rate (BER) and clear eye diagram were achieved for ROF and FTTX applications; and good performances of carrier-to-noise ratio (CNR), composite second-order (CSO) and composite triple beat (CTB) were obtained for CATV signals.

A novel hybrid three-band transport system based on a DFB LD with multi-wavelength output characteristic

Paper 7958-9 of Conference 7958
Date: Wednesday, 26 January 2011
Time: 2:50 PM – 3:20 PM

Author(s): Hai-Han Lu, Peng-Chun Peng, Hsiang-Chun Peng, Chung-Yi Li, Heng-Sheng Su, National Taipei Univ. of Technology (Taiwan)
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A potentially cost-effective radio-over-fiber (ROF)/fiber-to-the-X (FTTX)/CATV hybrid three-band transport system based on direct modulation of a distributed feedback laser diode (DFB LD) with multi-wavelength output characteristic is proposed and experimentally demonstrated. Directly modulated radio-frequency (RF) (1.25Gbps/6GHz), externally remodulated baseband (BB) (622 Mbps), and externally remodulated CATV (channels 2-78) signals are successfully transmitted simultaneously. Over an 80-km single-mode fiber (SMF) transmission, low bit error rate (BER) and clear eye diagram were achieved for ROF and FTTX applications; and good performances of carrier-to-noise ratio (CNR), composite second-order (CSO) and composite triple beat (CTB) were obtained for CATV signals.

Measuring the spatial distribution of rare-earth dopants in high-power optical fibers

Paper 7914-59 of Conference 7914
Date: Thursday, 27 January 2011
Time: 1:50 PM – 2:20 PM

Author(s): Andrew D. Yablon, Interfiber Analysis (United States)
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For the first time, a non-destructive technique for spatially resolving the location and relative concentration of rare-earth dopants in an optical fiber is demonstrated. This novel technique is based on computerized tomographic detection of spontaneous emission and achieves micron-scale spatial resolution. Recently, several groups have reported on performance benefits resulting from complex spatial distributions of rare-earth dopants in high-power optical fibers. The new technique can elucidate interactions between the signal, pump, and dopant distributions and also reveal shortcomings in fiber manufacturing. Experimental data obtained from commercially available Yb-doped optical fibers is presented.

Flexible hollow-fiber bundle for body temperature imaging

Paper 7894-45 of Conference 7894
Date: Sunday, 23 January 2011
Time: 5:10 PM – 5:30 PM

Author(s): Yuji Matsuura, Keisuke Naito, Tohoku Univ. (Japan)
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A flexible and coherent bundle of hollow optical fibers was fabricated for infrared thermal imaging. For acquisition of thermal images, differences in the transmission efficiency among the fibers were numerically compensated to obtain high temperature resolution of 1 degree C for measuring body temperature. In a lens system with 10-fold magnification and hollow fibers of 320-micron inner diameter, the spatial resolution is around 3 mm. The hollow-fiber bundle enables observation of the surface temperature of inner organs and blood flow of the surfaces when the bundle is introduced into the human body with an endoscope.

Side-pumped, tapered fiber bundle for all-fiber counter-propagating pumped high-power fiber amplifiers

Paper 7914-76 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Thomas Theeg, Katharina Hausmann, Maik Frede, Hakan Sayinc, Laser Zentrum Hannover e.V. (Germany) and QUEST - Ctr. for Quantum-Engineering and Space-Time Research (Germany); Jörg Neumann, Laser Zentrum Hannover e.V. (Germany); Dietmar Kracht, Laser Zentrum Hannover e.V. (Germany) and QUEST - Ctr. for Quantum-Engineering and Space-Time Research (Germany)
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We report an all-fiber side-pumped coupler for counter-propagating pumping of high power fiber amplifiers. The fused fiber bundle consists of up to 6 pump fibers with core diameters of 105 µm (NA 0.15 or 0.22) which were side-coupled to a double-clad fiber with a pump cladding diameter of 250 µm (NA 0.46) by using a coreless intermediate fiber. A coupling efficiency of typically > 90 % and a power handling of at least 25 W for each pump port was demonstrated. This is a promising technique to make side-pumped couplers for counter-propagating pumping that can handle hundreds of watts.

All-fiber single-mode PM thulium fiber lasers using femtosecond laser written fiber Bragg gratings

Paper 7914-17 of Conference 7914
Date: Monday, 24 January 2011
Time: 4:10 PM – 4:30 PM

Author(s): Christina Willis, Robert A. Sims, Lawrence Shah, Martin C. Richardson, CREOL, The College of Optics and Photonics, Univ. of Central Florida (United States); Jens Thomas, Rita Becker, Christian Voigtländer, Friedrich-Schiller-Univ. Jena (Germany); Andreas Tünnermann, Stefan Nolte, Friedrich-Schiller-Univ. Jena (Germany) and Fraunhofer Institute for Applied Optics and Precision Engineering (Germany)
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Two continuous wave Tm fiber lasers, at 1959 nm and 2055 nm respectively, were implemented using single mode PM silica fiber and femtosecond written fiber Bragg gratings (FBG). The laser cavity consisted of a 790 nm diode spliced to a highly reflective FBG and 2 m of active fiber. The laser output coupler was either the Fresnel reflection from the flat cleaved output fiber facet or a low reflectivity FBG. The best performance was achieved with the 1959 nm HR-LR FBG cavity, which yielded up to 5 W with 47.5% slope efficiency and 0.5 nm spectral width.

Research on the FBG's high-temperature sustainability influenced by the doping process

Paper 7894-3 of Conference 7894
Date: Saturday, 22 January 2011
Time: 8:40 AM – 9:00 AM

Author(s): Weijun Huang, Feng Tu, Yangtze Optical Fibre and Cable Co., Ltd. (China)
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This paper investigates the influence of dopant on the temperature sustainability of fiber Bragg gratings (FBGs) fabricated in Ge/B co-doped photosensitive optical fibers. The experimental results exhibit that the Boron dopant brings deleterious influence on the FBG's high-temperature sustainability. The FBG sustainable temperature will become lower than 500℃ when the boron concentration reaches 15% in germanium highly doped photosensitive fiber.

Spatially resolved probing of biological phantoms by point-radiance spectroscopy

Paper 7894-13 of Conference 7894
Date: Saturday, 22 January 2011
Time: 11:30 AM – 11:50 AM

Author(s): Serge Grabtchak, Tyler Palmer, William M. Whelan, Univ. of Prince Edward Island (Canada)
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Interstitial fiber-optic based strategies for therapy monitoring and assessment rely on detecting treatment-induced changes in a light distribution in tissues. We present an optical technique to identify spectrally and spatially tissue chromophores in Intralipid phantoms. Point radiance spectroscopy is based on directional light collection with a side-firing fiber rotated up to 360 degrees. Localized scatterers and absorbers were introduced into the phantom both on the axis between source and detector and off-axis. Localized optical inhomogeneities were detectable as angular-resolved variations in the radiance polar plots. This technique is being investigated as a non-invasive optical modality for prostate cancer monitoring.

Fabrication of silver-coated hollow fiber with an inner diameter of 100 µm or less

Paper 7894-14 of Conference 7894
Date: Saturday, 22 January 2011
Time: 11:50 AM – 12:10 PM

Author(s): Katsumasa Iwai, Sendai National College of Technology (Japan); Mitsunobu Miyagi, Tohoku Univ. (Japan); Yi-Wei Shi, Fudan Univ. (China); Yuji Matsuura, Tohoku Univ. (Japan)
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Extremely flexible hollow fibers with 100-μm-bore size or less were developed for infrared laser delivery. Fabrication process and transmission properties of the ultra-thin hollow fiber were discussed. The silver layer was inner-plated by using the conventional silver mirror-plating technique. Concerning the fabrication parameters used up to now for 320-μm bore-sized fibers, the target flowing rate for plating solutions was 10 ml/min. Parallel bundles of silica capillary were used to increase the cross-sectional area. To achieve the target, bundles with 560 pieces, 1200 pieces, and 9600 pieces were used for the capillary with inner diameters of 100-μm, 75-μm, and 50-μm, respectively. The loss for the 50-μm bore size, 10-cm length silver hollow fiber was 10 dB at the wavelength of 1 μm.

Modification of a long-period grating based fiber optic for DNA biosensing

Paper 7894-20 of Conference 7894
Date: Saturday, 22 January 2011
Time: 4:20 PM – 4:40 PM

Author(s): Michele Sozzi, Annamaria Cucinotta, Roberto Corradini, Rosangela Marchelli, Univ. degli Studi di Parma (Italy); Maria Konstantaki, Stavros Pissadakis, Foundation for Research and Technology-Hellas (Greece); Stefano Selleri, Univ. degli Studi di Parma (Italy)
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The feasibility of a biosensor for DNA label-free detection, based on long period fiber gratings, has been investigated. The surface of the grating has been functionalized with peptide nucleic acid (PNA) probes. DNA strands, matched with the PNA probes, have been immobilized on the surface itself. The possibility of a resonant wavelength shift in the transmission spectrum due to DNA capture will be discussed. Moreover, the problem of reusing the sensor for multiple measurements will also be addressed.

Fiber-based surface plasmon resonance sensor for neural recording from rat brain cortex

Paper 7894-31 of Conference 7894
Date: Sunday, 23 January 2011
Time: 10:30 AM – 10:50 AM

Author(s): Shinae Kim, Hyo Won Moon, Seoul National Univ. (Korea, Republic of); Jonghwan Lee, Harvard Medical School (United States); Kyung Min Byun, Kyung Hee Univ. (Korea, Republic of); Sung June Kim, Seoul National Univ. (Korea, Republic of)
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A fiber-based surface plasmon resonance (SPR) system has been developed for label-free detection of neural activity. The fiber-based SPR system was optimized for the cortical recording through modification of fiber design. Evoked neural responses were successfully detected from rat somatosensory cortex following electrical stimulation on a forepaw. Simultaneous electrical recording showed that the optical responses were highly correlated with electrical neural activities. Pharmacological experiments also confirmed that the optical signal was originated from the neural activity. This study demonstrates that the fiber-type SPR system can be used for a label- and artifact-free in vivo neural recording.

Course: Splicing of Specialty Fibers and Glass Processing of Fused Fiber Components

Date: Sunday, 23 January 2011
Time: 1:30 PM – 5:30 PM

Instructor(s): Baishi Wang, Vytran LLC (United States)
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This course provides attendees with the fundamental principles of specialty fiber splicing and glass fusion processing. The course first describes the fiber waveguides and the coupling optics associated with the process. It then focuses on practical fusion splicing methods to achieve high performance optical coupling between dissimilar specialty fibers. Fabrication techniques are discussed for producing high performance fused components, such as fiber combiners and couplers for fiber lasers and sensing applications. The course also describes several practical application examples and fusion hardware.

Integrating optical system designed for multimodal analysis of pearls and its mother oyster to distinguish and appraise cultured pearls

Paper 7892-28 of Conference 7892
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Myeong Jin Ju, Sang Jin Lee, Eun Jung Min, Yuri Kim, Do Hyung Kim, Gwangju Institute of Science and Technology (Korea, Republic of); Hae Yeon Kim, Korea Pearl Lab. (Korea, Republic of); Dong Seon Lee, Byeong-Ha Lee, Gwangju Institute of Science and Technology (Korea, Republic of)
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Integrating optical system combining optical coherence tomography (OCT) and fluorescence spectroscopy (FS) has been designed and utilized to distinguish mother oyster used in pearl culturing as well as discriminate and evaluate pearls, nondestructively. Especially, this system could be implemented in a simple and effective way with highly minimized polarization and group velocity dispersion (GVD) mismatch problems as applying common-path configuration. Different two types of measurements previously performed by two independent apparatus were made; the internal structure measurement and the fluorescence spectrum measurement. With this multifunctional modality, we believe, it would be possible multimodal analyzing for distinguishing and estimating cultured pearls.

1kW cw Yb-fiber-amplifier with <0.5GHz linewidth and near-diffraction limited beam-quality, for coherent combining application

Paper 7914-6 of Conference 7914
Date: Monday, 24 January 2011
Time: 10:50 AM – 11:10 AM

Author(s): Doruk Engin, Wei Lu, Mehmetcan Akbulut, Bruce McIntosh, Horacio R. Verdun, Shantanu Gupta, Fibertek, Inc. (United States)
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We report on SBS-free 1kW cw operation of multi-stage Yb-fiber-MOPA, having a phase-modulated linewidth of only 450MHz, with near diffraction-limited beam-quality, and high (>83%) internal quantum efficiency. The final amplifier stage uses very high Yb-doped 35-um core LMA fiber, using a new fiber process recipe that virtually eliminates photo-darkening. To enable true single-frequency cw operation at kW level, we investigate further mode-area scaling, with gain-discrimination for the higher-order modes. Partially Yb-doped cores with diameters up to 80-um were studied, where SBS-free single-frequency (few kHz) cw operation is obtained up to 0.9kW, although the beam-quality deteriorates for powers >200W. These results are in good agreement with a comprehensive model for kW LMA fiber amplifiers.

High-power, high-brightness, and low-weight fiber coupled diode laser device

Paper 7918-23 of Conference 7918
Date: Monday, 24 January 2011
Time: 11:00 AM – 11:20 AM

Author(s): Paul Wolf, Bernd Köhler, Karsten Rotter, Susanne Hertsch, Heiko Kissel, Jens Biesenbach, DILAS Diodenlaser GmbH (Germany)
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New solid-state laser devices, especially fiber laser systems, require increasingly higher optical output power provided by fiber-coupled diode laser pump modules. In particular for defense technology, robust but lightweight high-power diode laser sources with high brightness are needed. We present a detailed characterization of a diode laser source with 675 W of optical power coupled into a 200 µm, NA 0.22 fiber with a lightweight design due to a special housing optimized for low weight. Spectral quality is ensured over a wide range of temperature and current by means of volume holographic gratings. Nevertheless, an overall efficiency of more than 40 % has been achieved.

CPA-free picosecond fiber amplifier with >10μJ pulse energy and >300kW peak power

Paper 7925-27 of Conference 7925
Date: Monday, 24 January 2011
Time: 1:40 PM – 2:00 PM

Author(s): Yoann Zaouter, Maxime Lebugle, Franck Morin, Eric Mottay, Clemens Hönninger, Amplitude Systemes (France)
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We demonstrate a compact and robust picosecond fiber amplifier system that produces >10uJ pulse energy and average powers exceeding 10W while maintaining a narrow spectral bandwidth. This simple and compact CPA-free fiber amplifier system is well suited for micro-machining applications as well as for scientific applications that require narrow optical spectra as e.g. CARS spectroscopy.

Distribution of photodarkening-induced loss in Yb-doped fiber amplifiers

Paper 7914-20 of Conference 7914
Date: Monday, 24 January 2011
Time: 5:30 PM – 5:50 PM

Author(s): Michalis N. Zervas, Univ. of Southampton (United Kingdom)
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We report photodarkening-induced output power degradations and long-term stability in high power pulsed and CW fiber laser MOPA systems. The laser systems use aluminosilicate single-mode Yb-doped fibers and the GTWave fiber technology for cladding pumping. We have tested Yb-doped fiber amplifiers operated under both pulsed and CW mode. Using OTDR loss measurements we show, for the first time, that the photodarkening-induced loss is non-uniformly distributed along the length of the active fiber. By calculating the average inversion distribution, we show that the induced loss follows closely an Yb-inversion dependence to the power of 2.

Miniaturized fiber raster scanner for endoscopy

Paper 7895-32 of Conference 7895
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): David R. Rivera, Demirhan Kobat, Chris Xu, Cornell Univ. (United States)
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We demonstrate a novel hybrid resonant/non-resonant miniaturized raster scanner, fabricated by mounting a double clad fiber onto two perpendicularly oriented piezo bimorphs. The fiber scanner has a total length of 2.6cm, a width/thickness ≤1mm, achieves ≥800μm fiber tip deflection for both the resonant and non-resonant axes, and allows for imaging at approximately 4 frames per second (512 lines per frame). The small size allows for the fiber scanner to be easily packaged along with miniaturized lenses to form an endoscope for microscopic imaging. In order to demonstrate the fiber scanner's imaging capabilities, we have taken transmission and fluorescence images.


Synthesis of novel transparent glass ceramics containing rare earth ion-doped YLF nanocrystals for fiber amplifiers and fiber lasers

Paper 7934-2 of Conference 7934
Date: Tuesday, 25 January 2011
Time: 11:00 AM – 11:20 AM

Author(s): Takenobu Suzuki, Shin-ichiro Masaki, Kento Mizuno, Toyota Technological Institute (Japan); Shintaro Mizuno, Toyota Central Research and Development Labs., Inc. (Japan); Yasutake Ohishi, Toyota Technological Institute (Japan)
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Silicate based transparent glass ceramics containing YLF nanocrsystals have synthesized by conventional melt quenching of glass followed by controlled heat treatment of the precursor glass. X-ray diffraction powder pattern of the glass-ceramic revealed that precipitated crystalline phase was solely YLF. The averaged diameter of primary crystallites was roughly about 8 nm. When 0.1 mol.% of YF3 was substituted by ErF3, an emission at 980 nm with clear Stark splitting was observed by 800 nm excitation of glass ceramic though no emission was observed at the wavelength for the precursor glass. This indicates that rare-earth ions could be incorporated into YLF nanocrystals.

Polarization-purity spectra of a tapered-fiber-coupled microsphere cavity system at cryogenic temperatures

Paper 7913-43 of Conference 7913
Date: Tuesday, 25 January 2011
Time: 2:20 PM – 2:40 PM

Author(s): Masazumi Fujiwara, Akira Tanaka, Kiyota Toubaru, Hong-Quan Zhao, Hideaki Takashima, Shigeki Takeuchi, Osaka Univ. (Japan) and Hokkaido Univ. (Japan)
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We present our recent progress in the experiment of optical coupling between a microsphere cavity and a tapered fiber in cryogenic environment. We have developed a home-made liquid helium cryostat storing tapered-fiber-coupled microsphere cavity. The optical coupling was made at around 637 nm. To characterize the unwanted effect coming from the complicated cryogenic systems, we have measured the polarization purity (or degree of polarization) of light propagating in the tapered-fiber-coupled microsphere cavity at temperatures ranging from 8-30K. The results show that the purity at frequencies off-resonance to the cavity modes conserves against the temperature change, while the purity on-resonance fluctuates.

High-power actively mode-locked ytterbium doped fiber laser delivering 15 ps at 40 MHz

Paper 7914-34 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 2:50 PM – 3:10 PM

Author(s): Pierre Deslandes, Univ. Bordeaux 1 (France) and EOLITE Systems (France); Damien Sangla, Eric Freysz, François Salin, Julien Saby, Univ. Bordeaux 1 (France)
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We present the realization of an actively mode-locked laser based on a 15 um core diameter singlemode double clad photonic crystal fiber. We achieved an average power of 2 W at 40 MHz for 6 W of pump power. We measured a pulse duration of 15 ps. This corresponds to an energy of 50 nJ per pulse and a peak power of 3.3 kW.

High-energy Yb-doped fiber MOPA in the ns-kHz regime for large-scale laser facilities front-end

Paper 7914-35 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 3:10 PM – 3:30 PM

Author(s): Laure Lago, Commissariat à l'Énergie Atomique (France); Arnaud Mussot, Marc Douay, Univ. des Sciences et Technologies de Lille (France); Emmanuel Hugonnot, Commissariat à l'Energie Atomique (France)
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We present a dual-stage fibered Master Oscillator Power Amplifier system designed to meet stringent requirements of large-scale laser facilities front-end sources. Strictly single mode beam, narrow-bandwidth (100 pm) 10 kHz nanosecond pulse amplification up to 0.5 mJ is obtained inside large mode area microstructured fibres, with more than 40 dB optical signal-to-noise ratio, 25 dB polarization extinction ratio and sub-nanosecond resolution temporal shaping. These results are in excellent agreement with numerical simulations including forward and backward Amplified Spontaneous Emission.

High-pulse energy operation of efficient and compactly packaged, ns-pulse Yb-doped photonic-crystal fiber-based lasers delivering high-spectral and spatial brightness

Paper 7914-30 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 5:20 PM – 5:40 PM

Author(s): Fabio Di Teodoro, Northrop Grumman Aerospace Systems (United States)
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We describe two examples of compactly packaged, actively triggered master-oscillator/power-amplifier (MOPA) systems featuring segmented, Yb-doped 100um-core rod-type polarization-maintaining PCFs (largest-core PCF to date) as the final amplifiers. In the first, a single MOPA packaged within a <15-liter volume enclosure generates linearly polarized, ~1.5ns-duration, 10-kHz pulse repetition frequency (PRF) pulses of energy/peak power > 2mJ/1.5MW, M2 ~ 1.2, and >85% pulse energy into a 0.06nm window. In the second architecture, four time-synchronizable MOPAs, each of which produces ~50W average-power, 50kHz-PRF, <2ns pulses, are packaged in a 48×35×18cm enclosure, which also incorporates a setup for dense wavelength multiplexing of the MOPA outputs.

High-pulse energy operation of efficient and compactly packaged, ns-pulse Yb-doped photonic-crystal fiber-based lasers delivering high-spectral and spatial brightness

Paper 7912-30 of Conference 7912
Date: Tuesday, 25 January 2011
Time: 5:20 PM – 5:40 PM

Author(s): Fabio Di Teodoro, Northrop Grumman Aerospace Systems (United States)
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We describe two examples of compactly packaged, actively triggered master-oscillator/power-amplifier (MOPA) systems featuring segmented, Yb-doped 100um-core rod-type polarization-maintaining PCFs (largest-core PCF to date) as the final amplifiers. In the first, a single MOPA packaged within a <15-liter volume enclosure generates linearly polarized, ~1.5ns-duration, 10-kHz pulse repetition frequency (PRF) pulses of energy/peak power > 2mJ/1.5MW, M2 ~ 1.2, and >85% pulse energy into a 0.06nm window. In the second architecture, four time-synchronizable MOPAs, each of which produces ~50W average-power, 50kHz-PRF, <2ns pulses, are packaged in a 48×35×18cm enclosure, which also incorporates a setup for dense wavelength multiplexing of the MOPA outputs.

Characterization of modal coupling of Bragg gratings in large-mode-area fibers

Paper 7914-70 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Aarni T. Iho, Ari Tervonen, Aalto Univ. School of Science and Technology (Finland); Kalle Ylä-Jarkko, Corelase Oy (Finland); Simo Tammela, Beneq Oy (Finland); Seppo K. Honkanen, Aalto Univ. School of Science and Technology (Finland)
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A new measurement technique for characterizing the effects of coupling of power from the fundamental mode to higher order core and cladding bounded modes occurring in a fiber Bragg grating (FBG) inscribed in a large-mode-area (LMA) fiber is demonstrated and studied. The method is based on inducing mode selective fiber bending losses on the modes propagating in the core and monitoring the power guided by the cladding of the LMA fiber. Besides transmitted, also reflected distributions of modes can be resolved in terms of the relative powers carried by them and thus the fraction of higher order modes (HOM) can be quantified.

Group-velocity dispersion in multimode photonic crystal fibers measured using time-domain white-light interferometry

Paper 7914-73 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Pascal Böswetter, Tobias Baselt, Frank Ebert, Fabiola Basan, Peter Hartmann, West Saxon Univ. of Applied Sciences Zwickau (Germany)
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The dispersion and modal properties of photonic crystal fibers (PCF) strongly depend on structural parameters. Since fabrication tolerances affect the structure of the photonic lattice the dispersion behavior as well as the number of guided transverse modes can differ from numerical calculations. To measure the dispersion of optical fibers with high accuracy, a time-domain white-light interferometer is used. The experimental setup operates in the range from 630 nm to 1550 nm. This paper demonstrates a simple yet effective way to suppress higher-order modes to measure the dispersion of single-mode and multimode photonic crystal fibers as well.

Guiding and birefringent properties of a hybrid PDMS/silica photonic crystal fiber

Paper 7914-78 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Christos Markos, National Hellenic Research Foundation (Greece); Kyriakos G. Vlachos, Univ. of Patras (Greece); George Kakarantzas, National Hellenic Research Foundation (Greece)
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In this paper, we present the direct modification of a highly birefringent (Hi-Bi) Photonic Crystal Fiber (PCF) by infiltrating the air holes of the PCF with PDMS elastomer. Due to high thermo-optic coefficient of the elastomeric inclusions, the fiber exhibits high sensitivity to external perturbations such as temperature. We have numerically investigated the TIR-based guiding mechanism and polarization properties of the hybrid structure based on Finite Difference Time Domain (FDTD) analysis. We also experimentally demonstrate the device's sensitivity and the thermo-optic effect of the elastomer into the holes of PCF for a range of temperatures up to 80°C.

High power red laser oscillation in Pr3+-doped waterproof fluoro-aluminate glass fiber excited by a GaN laser diode

Paper 7912-79 of Conference 7912
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Jun Nakanishi, Tsuyoshi Yamada, NIDEK Co., Ltd. (Japan); Yasushi Fujimoto, Osaka Univ. (Japan); Osamu Ishii, Masaaki Yamazaki, Sumita Optical Glass, Inc. (Japan)
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We have demonstrated a high power fiber laser with a Pr3+-doped waterproof fluoro-aluminate glass fiber (Pr:WPFGF) that directly oscillates visible laser beam using a blue/violet GaN laser diode as the pumping light. Only the wavelength of 638 nm was selectively oscillated using dielectric-multilayered-coatings deposited at both end surfaces of the Pr:WPFGF. The maximum output power was measured to be 311.4 mW at 800 mW pumping power. The slope efficiency was calculated to be 41.6%. The slope efficiency at a low output power showed good agreement with our theoretical prediction (44.2%).

High-gain resonance Er:glass amplifier

Paper 7914-102 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Peng Wan, Jian Liu, PolarOnyx, Inc. (United States)
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By using a resonant cavity, a novel and compact hybrid amplifier has been demonstrated. The seeding laser is a pulse shaping fiber laser, which can generate both CW and pulse outputs at an eye safe wavelength of 1550 nm. By using Er3+/Yb3+ co-doped phosphate glass this resonant amplifier was tested for both CW and pulsed input with repetition rates varying from a few Hz to 250 kHz. A gain of 20 dB was obtained for nanosecond pulses. High OSNR, high extinction ratio and low background noise were also achieved by our new amplification method.

High-power double-clad Er-doped fiber laser

Paper 7914-75 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Mikhail Likhachev, Leonid Kotov, Mikhail M. Bubnov, Oleg I. Medvedkov, A. M. Prokhorov General Physics Institute (Russian Federation); Denis Lipatov, Institute of Chemistry of High-Purity Substances of the Russian Academy of Sciences (Russian Federation); Aleksey N. Guryanov, A. M. Prokhorov General Physics Institute (Russian Federation)
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In this paper, we propose a novel all-fiber laser scheme with the output wavelength 1560 nm based on a new Er-doped fiber design. A conventional commercially available pump source at 980nm (D=105um, NA=0.2) is used for pumping. A high slope efficiency of 30 % comparable with those in Er-Yb lasers was achieved owing to utilization of the novel P2O5-Al2O3-SiO2 (PAS) glass as the host for Er3+ ions. A relatively low in-cavity fiber length (~10m) become possible owing to a small outer fiber diameter (80um) and the use of a fiber taper (105um to 80um) for launching the pump.

Photodarkening-induced refractive index change in ytterbium doped fibers

Paper 7914-81 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Changgeng Ye, Joan J. Montiel i Ponsoda, Ari Tervonen, Seppo K. Honkanen, Aalto Univ. School of Science and Technology (Finland)
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By using a modal interference method, photodarkening-induced refractive index change in ytterbium doped fibers is measured with high accuracy. This refractive index change is positive at the ytterbium lasing wavelengths near 1080nm, and it gradually approaches a saturated level. It is found that the refractive index change is linearly proportional to the photodarkening-induced excess loss at an arbitrary probe wavelength in the visible band. The maximum refractive index change in our experiment is close to 1×10-5, measured from different ytterbium fiber samples. The influence of the photodarkening-induced refractive index change on fiber lasers is discussed.

Yb-doped fiber amplifiers at 1014.8 nm and frequency quadrupling

Paper 7914-72 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Tao Hong, Shanghai Institute of Optics and Fine Mechanics (China) and Shanghai Advanced Research Institute (China)
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We report our recent progress toward making a narrow-linewidth, 2-stage Yb-doped double-clad fiber amplifier at 1014.8nm and frequency quadrupling of this laser for 253nm. A narrow-linewidth continuous-wave semiconductor laser, tunable around 1014.8 nm, is used as a seed, feeding into the fiber amplifier, pumped by diode lasers at 980nm via fiber combiners. The gain fibers are cooled to liquid-nitrogen temperatures in order to suppress the absorption at the operating wavelength. The anticipate power could be multi-Watt. The emission will then be frequency quadrupled with optical cavities to achieve 253nm and used for laser cooling of mercury as a source for the new generation of optical frequency standards. This work is supported by Research Project of Shanghai Science and Technology Commission (Grant. No. 09DJ1400700) and National Natural Science Foundation of China (Grant No. 10974211).

Robust single-mode ytterbium-doped large pitch fiber emitting 294 W

Paper 7914-42 of Conference 7914
Date: Wednesday, 26 January 2011
Time: 9:20 AM – 9:40 AM

Author(s): Florian Jansen, Fabian Stutzki, Tino Eidam, Cesar Jauregui, Jens Limpert, Andreas Tünnermann, Friedrich-Schiller-Univ. Jena (Germany)
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High average power is extracted from a short-length large pitch photonic crystal fiber (LPF) amplifier with nearly diffraction limited beam quality. The fibers used in the experiments exhibit a robust single mode behaviour even under x-y-misalignment of the seed coupling. The amplifier output power reaches 294W with a simulated and measured mode field diameter of ~62µm. The M² was measured to be <1.4 due to the hexagonal shape of the fundamental mode, which is in good agreement with numerical simulations. Thus, the pointing stability remains excellent.

4-kW fiber laser for metal cutting and welding

Paper 7914-43 of Conference 7914
Date: Wednesday, 26 January 2011
Time: 9:40 AM – 10:00 AM

Author(s): Dahv A. V. Kliner, Kwang Chong, Justin Franke, Thomas E. Gordon, Jeff G. Gregg, Vincent M. Issier, Boris M. Kharlamov, Andrea Kliner, Masanao Kobayashi, Juan Lugo, Johnny Luu, James J. Morehead, Martin H. Muendel, Lawrence E. Myers, Kelvin Nguyen, JDSU (United States); Hiroshi Sako, Amada Co., Ltd. (Japan); Kyle R. Schneider, Jeff Segall, Katherine Shigeoka, JDSU (United States); Daniel B. Soh, Sandia National Labs., California (United States); Raman Srinivasan, Derek Tucker, Dirk Woll, David L. Woods, Hongbo Yu, Chris Zhang, JDSU (United States)
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We have developed a commercial 4-kW fiber laser consisting of seven, 600-W modules whose outputs are combined with a fused-fiber combiner. The system architecture has several practical advantages, including pumping with reliable single-emitter diodes, monolithic construction (no free-space beams), and end pumping using a 91:1 pump combiner (eliminating the need for complex pump/signal combiners). At 4 kW power, the beam-parameter product is 2.5 mm-mrad, the 8-hr power stability is 0.02% rms, the central wavelength is 1081 nm, and the linewidth is 1.2 nm FWHM. These lasers have been incorporated into Amada machines used for cutting metal sheet and plate.

Long period and fiber Bragg gratings written within the same fibre for sensing purposes

Paper 7941-40 of Conference 7941
Date: Wednesday, 26 January 2011
Time: 11:10 AM – 11:30 AM

Author(s): Francesco Baldini, Massimo Brenci, Ambra Giannetti, Riccardo Falciai, Cosimo Trono, Istituto di Fisica Applicata Nello Carrara (Italy); Francesco Chiavaioli, Marco Mugnaini, Univ. degli Studi di Siena (Italy)
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Long period gratings (LPGs) have been proposed as sensing elements of chemical/biochemical compounds, exploiting their sensitivity to refractive index changes in surrounding environment. The difficulty of their utilization as chemical/biochemical sensors comes from their dependence also to strain and temperature effects. An intrinsic optical feedback to eliminate these effects was developed by manufacturing on the same fiber containing the LPG, a fiber Bragg grating immune from refractive index changes external to the fiber, but influenced by strain and temperature. An automatic correction of the signals from the two gratings allows to eliminate any effect coming from strain and/or temperature changes.

Passive fiber ring as a device for effective refractive index measurement

Paper 7934-54 of Conference 7934
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Vladimir Vašinek, Jan Latal, Petr Koudelka, Jan Vitasek, Petr Siska, Jan Skapa, Technical Univ. of Ostrava (Czech Republic)
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The article deals with topics about fiber optic ring, evaluation of the signals delay in the ring and in case of the first designed arrangement measurement of the fiber length. The second task is to detect the effective refractive index n1eff of the fiber core at the given length of ring. Author's team gradually discusses how configurations for the tasks are created. Fiber ring is created with G.652 optical fiber and laser diode operates both 1310 and 1550 nm.

Cylindrical vector beam generation from a multicore optical fiber

Paper 7950-18 of Conference 7950
Date: Thursday, 27 January 2011
Time: 9:00 AM – 9:20 AM

Author(s): Giovanni Milione, Henry I. Sztul, Robert R. Alfano, The City College of New York (United States); Daniel A. Nolan, Michael Etienne, Joseph McCarthy, Ji Wang, Corning Inc. (United States)
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A method for the generation of cylindrical vector beams based on the design of a multicore optical fiber is presented. This design consists of N elliptical cores symmetrically arranged in a circular array about the fiber axis, where the orientation of each core's major axes has an azimuthally varying distribution. Coherent superposition of the azimuthally distributed polarization outputs from each individual core in the far field produces a cylindrically symmetric amplitude and polarization state. Fibers with N=6 cores of varying diameter and core size are fabricated and experimentally investigated.

Graphene mode locked ultrafast fiber lasers

Paper 7914-53 of Conference 7914
Date: Thursday, 27 January 2011
Time: 9:30 AM – 10:00 AM

Author(s): Dingyuan Tang, Han Zhang, Nanyang Technological Univ. (Singapore); Qiaoliang Bao, Kian Ping Loh, National Univ. of Singapore (Singapore)
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We show experimentally that graphene possesses ultrafast saturable absorption, which can be used for mode locking of fiber lasers. Either the pristine graphene or graphene-polymer nanocomposite was used for mode locking erbium-doped fiber lasers. It was found that stable mode locked pulses could always be obtained, and the mode locked pulses could have much larger energy than those obtained with SESAM or CNT mode locking techniques. A unique property of graphene saturable absorption is its wavelength independence. Taking advantage of the property we have achieved wide range (~ 30nm) wavelength tunable soliton operation in erbium-doped fiber lasers. In addition, a graphene mode locked Yb-doped fiber laser operating at 1.06 micrometer was also demonstrated.

High-energy fibre CPA system based on a single stage rod type fiber amplifier in double pass configuration

Paper 7914-55 of Conference 7914
Date: Thursday, 27 January 2011
Time: 11:00 AM – 11:20 AM

Author(s): Yoann Zaouter, Franck Morin, Clemens Hönninger, Eric Mottay, Amplitude Systemes (France)
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We report the generation of high energy, high temporal quality ultrashort pulses from a compact non-linear FCPA setup. The main amplifier uses a state-of-the-art Yb-doped fiber in a double-pass architecture. Thanks to sufficient pulse stretching and good management of dispersion and non-linearities in the system, 250fs pulses with excellent temporal quality and energies of up to 200µJ are extracted from the system. The achieved pulse peak power of ~750MW is among the highest ever generated by a fiber CPA while the optical setup only requires one single power amplifier and fits in a 1.2m x 0.45m x 0.12m housing.

A conceptual study of a fiber-optical approach to solid-state laser cooling

Paper 7951-8 of Conference 7951
Date: Thursday, 27 January 2011
Time: 11:40 AM – 12:10 PM

Author(s): Dan T. Nguyen, College of Optical Sciences, The Univ. of Arizona (United States); Jianfeng Wu, Zhidong Yao, Jie Zong, Arturo Chavez-Pirson, NP Photonics, Inc. (United States); Jeff Weiss, Christopher Shanor, Rudolf Binder, College of Optical Sciences, The Univ. of Arizona (United States)
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We present a conceptual approach to the cooling of electronic devices using an integrated fiber optical system. Our study responds to a recent solicitation by the Office of Naval Research of utilizing the benefits of optical fiber technology to the all-optical cooling of high-power RF devices used in communication networks. In particular, remote heat dumping is a key benefit of these envisioned cooling systems. We have designed a first-generation all-fiber cooling system and present a theoretical and experimental study, addressing the main advantages as well as important challenges for future generations of all-fiber laser cooling systems.

High-power dissipative soliton laser using chirally-coupled core fiber

Paper 7914-60 of Conference 7914
Date: Thursday, 27 January 2011
Time: 2:20 PM – 2:40 PM

Author(s): Simon Lefrancois, Frank W. Wise, Cornell Univ. (United States); Thomas S. Sosnowski, Arbor Photonics, Inc. (United States); Almantas Galvanauskas, Univ. of Michigan (United States); Chi-Hung Liu, Arbor Photonics, Inc. (United States)
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We report an ultrafast modelocked laser based on large mode-area Chirally-Coupled Core fiber and dissipative soliton pulse shaping. An all-normal dispersion cavity delivers chirped pulse energies above 40 nJ that dechirp below 200 fs, with average powers above 2 W. Peak power is measured in excess of 125 kW. Numerical simulations confirm dissipative soliton pulse shaping. Using a shorter cavity, pulses as short as 105 fs are obtained. This demonstrates that Chirally-Coupled Core fiber delivers sufficiently single-mode performance for systems as sensitive as mode-locked oscillators, while enabling fused fiber component integration.

M2-characterization of beams emerging from LMA fibers by means of modal decomposition

Paper 7914-63 of Conference 7914
Date: Thursday, 27 January 2011
Time: 3:20 PM – 3:40 PM

Author(s): Daniel Flamm, Oliver A. Schmidt, Christian Schulze, Michael R. Duparré, Friedrich-Schiller-Univ. Jena (Germany); Siegmund Schröter, Institut für Photonische Technologien e.V. (Germany)
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We report on a fast measurement procedure for the widespread beam propagation ratio of light emerging from LMA fibers. The investigated beam is decomposed into its eigenmodes using a computer generated holographic filter. The modally resolved measurement of amplitudes and phases enables the reconstruction of the optical field. With the full field information, the propagation of the beam through free space is simulated and a virtual caustic measurement is realized. After comparing the presented method with ISO-standard measurements it is applied to conventional step-index fibers and to more sophisticated waveguides like photonic crystal fibers and multicore fibers.

Recent status and prospects of the EU-funded ALPINE project

Paper 7921-26 of Conference 7921
Date: Thursday, 27 January 2011
Time: 3:35 PM – 4:00 PM

Author(s): Stefano Selleri, Univ. degli Studi di Parma (Italy)
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The EU ALPINE project aims to push forward the research on laser systems for the scribing of photovoltaic modules, by developing low cost, high energy, short pulse, all-in-fiber lasers for IR, visible and UV micromachining. A necessary requirement for these innovative systems is having very large mode area single-mode fibers and interfacing technologies enabling these to be integrated into laser systems. ALPINE is also expected to provide CdTe/CdS and CuInGaSe2/CdS thin film solar cells on rigid and flexible substrates. These different configurations pose challenges to the patterning processes P1, P2, P3, all of them targeted with fully laser-based scribing.


Recent status and prospects of the EU-funded ALPINE project

Paper 7920-26 of Conference 7920
Date: Thursday, 27 January 2011
Time: 3:35 PM – 4:00 PM

Author(s): Stefano Selleri, Univ. degli Studi di Parma (Italy)
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The EU ALPINE project aims to push forward the research on laser systems for the scribing of photovoltaic modules, by developing low cost, high energy, short pulse, all-in-fiber lasers for IR, visible and UV micromachining. A necessary requirement for these innovative systems is having very large mode area single-mode fibers and interfacing technologies enabling these to be integrated into laser systems. ALPINE is also expected to provide CdTe/CdS and CuInGaSe2/CdS thin film solar cells on rigid and flexible substrates. These different configurations pose challenges to the patterning processes P1, P2, P3, all of them targeted with fully laser-based scribing.

Low-NA single-mode LMA photonic crystal fiber amplifier

Paper 7914-64 of Conference 7914
Date: Thursday, 27 January 2011
Time: 4:10 PM – 4:40 PM

Author(s): Thomas T. Alkeskjold, NKT Photonics A/S (Denmark)
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Enabling Single-Mode (SM) operation in Large-Mode-Area (LMA) fiber amplifiers is of high importance, since a SM output ensures highest beam quality and good pointing stability. In this paper, a new design approach for achieving ultra-low NA SM fibers is demonstrated. The design achieves SM operation even in short and straight fibers and allows relatively large preform tolerances to be compensated during draw. A low-NA SM fiber with mode field diameter > 55µm at 1064nm is demonstrated.

Effective absorption in cladding-pumped fibers

Paper 7914-65 of Conference 7914
Date: Thursday, 27 January 2011
Time: 4:40 PM – 5:00 PM

Author(s): Michalis N. Zervas, Univ. of Southampton (United Kingdom)
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In this talk we investigate for the first time experimentally and theoretically the wavelength dependence of the pump absorption along Yb3+-doped fibers, for cladding-pumped single as well as coupled multimode (GTWave) fibers. We show that significant spectral absorption distortions occur along the length with the 976nm absorption peak affected the most. We use a novel theoretical approach based coupled mode theory to explain the observed effects. We have also investigated the mode mixing requirements in order to improve the absorption spectral distribution along the increase the overall absorption efficiency and discuss the implications on fiber laser performance.

Course: Ultrafast Fiber Lasers

Date: Sunday, 23 January 2011
Time: 8:30 AM – 12:30 PM

Instructor(s): Martin E. Fermann, IMRA America, Inc. (United States)
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Starting from an introduction to fiber lasers, basic properties of fiber amplifiers are reviewed and current state of the art fiber amplifier technology is summarized. The course then describes preferred construction methods for ultrafast fiber lasers and frequency combs and discusses their applications in a variety of optical systems. The course covers mode locked fiber oscillators, phase stabilization techniques, supercontinuum sources, ultrafast fiber amplifiers, frequency converters as well as pulse compressors. Numerous design examples are given, illustrating the recurring physical phenomena governing these systems. The attendee learns about preferred methods for pico- and femtosecond pulse generation in compact fiber systems and basic modeling techniques for pulse evolution, stability, jitter and noise. The course concludes with overviews of applications in materials processing, frequency metrology, spectroscopy and optical sampling.

Course: Biomedical Fiber Optic Sensors and Applications

Date: Monday, 24 January 2011
Time: 8:30 AM – 12:30 PM

Instructor(s): Alexis Mendez, MCH Engineering LLC (United States); Robert A. McLaughlin, The Univ. of Western Australia (Australia)
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This course provides a broad overview of optical fiber sensing principles and techniques for biological and medical applications. The course is divided into two parts. Part I provides an introduction to fiber optic sensor (FOS) technology. This includes their operating principles, associated components (such as light sources, detectors, couplers, polarizers, etc.), and the specialty fiber types required for biomedical sensing system integration. In Part II, a review of the major classes of biomedical fiber sensors and techniques is made (based on VIS-UV-IR absorption, scattering, spectroscopy, fluorescence-among others), along with discussions on detection techniques, data analysis and interpretation. In addition, since some types of biomedical FOS rely, directly or indirectly, on visual or spectral imaging, the relevant image processing techniques and associated algorithms will also be discussed.

New broad spectrum fiber for medical and industrial fiber sensor applications

Paper 7894-48 of Conference 7894
Date: Saturday, 22 January 2011
Time: 1:20 PM – 1:40 PM

Author(s): John H. Shannon, Richard J. Timmerman, Valery K. Khalilov, Polymicro Technologies, A Subsidiary of Molex Incorporated (United States); Karl-Friedrich Klein, Univ. of Applied Sciences, Giessen Friedberg (United States)
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A new silica-based fiber design has been developed which exhibits improved transmission properties over a very wide spectral range. In the near infrared wavelength region, the attenuation of the new fiber is similar to standard NIR-fibers having a low OH silica core and F-doped cladding. Simultaneously, the fiber has excellent UV transmission down to 200nm comparable to standard high OH fibers. Additionally, the UV-defect concentrations in this low OH fiber have been reduced significantly, such that the solarization degradation properties are close to UV optimized high OH fibers with high radiation resistance. First results of spectral performance testing are given using different light sources, including deuterium lamp, tungsten-halogen lamp and laser-driven broadband light source. In addition, the test results evaluating UV solarization are reviewed. Finally, potential applications in the medical and industrial fiber sensing field will be discussed.

Laser beam uniformity and stability using homogenizer based fiber optic launch method: square core fiber delivery

Paper 7894-39 of Conference 7894
Date: Sunday, 23 January 2011
Time: 1:40 PM – 2:00 PM

Author(s): Todd E. Lizotte, Hitachi Via Mechanics (USA), Inc. (United States)
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Over the years, technological achievements within the laser medical diagnostic, treatment, and therapy markets have led to ever increasing requirements for greater control of critical laser beam parameters. Increased laser power/energy stabilization, temporal and spatial beam shaping and flexible laser beam delivery systems with ergonomic focusing or imaging lens systems are sought by leading medical laser system producers. This paper covers the use of fiber optic beam delivery as a means of defining the beam shape (intensity/power distribution uniformity) at the target plane as well as the use of fiber delivery as a means to allow more flexible articulation of the laser beam over the surface being treated.

Experimental investigation of suppressing stimulated Raman scattering in double clad fiber amplifiers employing long period gratings

Paper 7914-11 of Conference 7914
Date: Monday, 24 January 2011
Time: 1:30 PM – 1:50 PM

Author(s): Dirk Nodop, Cesar Jauregui-Misas, Florian Jansen, Jens Limpert, Andreas Tünnermann, Friedrich-Schiller-Univ. Jena (Germany)
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The first experimental investigation of the suppression of stimulated Raman scattering (SRS) employing long period gratings in double clad fiber amplifiers is presented. The long period gratings (LPGs), fabricated with a CO2-Laser, achieve SRS suppression by coupling the Stokes wavelength from the active core into the cladding. With only three LPGs inserted into a fiber pulse amplifier, the extractable Raman free output power was nearly doubled. A numerical simulation of the setup shows good agreement with the experimentally obtained results. The scaling potential of this approach is discussed.

575 nm laser oscillation in Dy3+-doped waterproof fluoro-aluminate glass fiber pumped by violet GaN laser diodes

Paper 7912-20 of Conference 7912
Date: Monday, 24 January 2011
Time: 4:40 PM – 5:00 PM

Author(s): Yasushi Fujimoto, Osaka Univ. (Japan); Osamu Ishii, Masaaki Yamazaki, Sumita Optical Glass, Inc. (Japan)
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We successfully drew a low-loss Dy-doped optical fiber (0.3dB/m at 532nm) of a waterproof fluoro-aluminate glass system and demonstrated yellow laser oscillation in the Dy3+-doped fluoride fiber pumped by a 398.8-nm violet GaN laser diode. The maximum output power was 10.3 mW and the slope efficiency was 17.1% at 575 nm. Since the fluoro-aluminate-glass system has a remarkable water resistance advantage compared to ZBLAN glass, Dy-doped fluoro-aluminate glass fiber is expected to contribute to making a solid-state yellow fiber laser with high chemical durability without a frequency doubling technique.

575 nm laser oscillation in Dy3+-doped waterproof fluoro-aluminate glass fiber pumped by violet GaN laser diodes

Paper 7917-20 of Conference 7917
Date: Monday, 24 January 2011
Time: 4:40 PM – 5:00 PM

Author(s): Yasushi Fujimoto, Osaka Univ. (Japan); Osamu Ishii, Masaaki Yamazaki, Sumita Optical Glass, Inc. (Japan)
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We successfully drew a low-loss Dy-doped optical fiber (0.3dB/m at 532nm) of a waterproof fluoro-aluminate glass system and demonstrated yellow laser oscillation in the Dy3+-doped fluoride fiber pumped by a 398.8-nm violet GaN laser diode. The maximum output power was 10.3 mW and the slope efficiency was 17.1% at 575 nm. Since the fluoro-aluminate-glass system has a remarkable water resistance advantage compared to ZBLAN glass, Dy-doped fluoro-aluminate glass fiber is expected to contribute to making a solid-state yellow fiber laser with high chemical durability without a frequency doubling technique.

Coherent monolithic THz generation based on quasi-phase-matched GaP bonding structures pumped by pulsed fiber lasers at ~ 1.5 μm

Paper 7917-16 of Conference 7917
Date: Tuesday, 25 January 2011
Time: 2:00 PM – 2:20 PM

Author(s): Wei Shi, NP Photonics, Inc. (United States); Eliot B. Petersen, NP Photonics, Inc. (United States) and The Univ. of Arizona (United States); Arturo Chavez-Pirson, NP Photonics, Inc. (United States); Nasser Peyghambarian, NP Photonics, Inc. (United States) and The Univ. of Arizona (United States)
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We report the coherent monolithic THz generation by using GaP QPM bonding structures based on difference-frequency generation (DFG) pumped by the pulsed fiber lasers in the C-band. The highest average power is about 10.9 uW at 1.5 THz by using 6-period GaP QPM bonding structure. Comparing with the single layer GaP crystal, 6-period GaP QPM bonding structure has 26 times of enhancement in THz generation. The azimuthal dependence of the THz generation for the GaP QPM bonding structure has been measured when the polarization directions of two pump beams are orthogonal and parallel, respectively.

Fused fiber pump and signal combiners for a 4-kW ytterbium fiber laser

Paper 7914-110 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Dirk Woll, Johnny Luu, Chris Zhang, James J. Morehead, Jeff Segall, Kuochou Tai, Boris M. Kharlamov, Hongbo Yu, Lawrence E. Myers, Martin H. Muendel, JDSU (United States)
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We report the development of fused-fiber pump and signal combiners, which are key enabling components of a 4-kW fiber laser. The fiber laser consists of seven laser modules, which are end-pumped through 91:1 fused-fiber combiners, yielding 900 W of nominal pump power. The high-brightness radiation of the modules is combined into a single output fiber using a 7:1 signal combiner, providing a total power of 4.1 kW in the single output beam. The beam parameter product of the combined output is 2.5 mm-mrad. The measured signal combiner insertion loss of 2% indicates power-handling capabilities beyond 4 kW.

Statistical properties of partially coherent CW fiber lasers

Paper 7917-69 of Conference 7917
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Dmitriy V. Churkin, Institute of Automation and Electrometry (Russian Federation); Sergey V. Smirnov, Novosibirsk State Univ. (Russian Federation); Evgenii V. Podivilov, Institute of Automation and Electrometry (Russian Federation)
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A detailed quantitative numerical analysis of partially coherent quasi-CW fiber laser is performed on the example of high-Q cavity Raman fiber laser (RFL). The key role of precise spectral performances of fiber Bragg gratings forming the laser cavity is clarified. It is shown that cross phase modulation between the pump and Stokes waves does not affect the generation. Amplitudes of different longitudinal modes constituting the generation spectrum strongly fluctuate obeying the Gaussian distribution. As intensity statistics is noticeably non-exponential and power dependent, longitudinal modes should be correlated.

Thermal modeling of active fiber and splice points in high-power fiber laser

Paper 7914-105 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Ziyan Huang, Tze Yang Ng, Chu Perng Seah, DSO National Labs. (Singapore); Hui Ting Lim, Nanyang Technological Univ. (Singapore); Ruifen Wu, DSO National Labs. (Singapore)
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A unique thermal FEM Model supported by experimental data has been successfully developed for the study of splicing joint in high power fiber laser, which is the main weakness for >100s watt fiber laser. Unlike previous works, surface temperature monitoring of the fiber with pumping power up to 430W under various cooling configurations, followed by the adjustment of heat load magnitude in FEM software to match these temperatures, reliably characterizes heating in splices. This leads to an accurate prediction of the splice point temperature at higher power. Excellent agreement between modeling and experimental data was achieved.

Fibers and fiber-optic components for high-power fiber lasers

Paper 7914-39 of Conference 7914
Date: Wednesday, 26 January 2011
Time: 8:00 AM – 8:30 AM

Author(s): Hagen Zimer, JT Optical Engine GmbH + Co. KG (Germany); Marcin M. Kozak, JENOPTIK Optical Systems GmbH (Germany); Andreas Liem, JT Optical Engine GmbH + Co. KG (Germany); Frank Flohrer, JENOPTIK Optical Systems GmbH (Germany); Falk Dörfel, JENOPTIK Laser GmbH (Germany); Peter Riedel, Guided Color Technologies GmbH (Germany); Sebastian Linke, Friedrich-Schiller-Univ. Jena (Germany); Ray J. Horley, Fabio Ghiringhelli, A. Harker, Sebastien Desmoulins, Michalis N. Zervas, SPI Lasers (United Kingdom); Johannes Kirchhof, Sonja Unger, Sylvia Jetschke, Institut für Photonische Technologien e.V. (Germany); Thomas Peschel, Thomas Schreiber, Fraunhofer-Institut für Angewandte Optik und Feinmechanik (Germany)
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The major challenge in the development of monolithic kW class cw fiber lasers is the efficient conversion of pump photons into a high brightness laser beam under the constraints of heat management, long term stability and nonlinearities. This article reviews the interaction of some fiber related aspects as e.g. fiber core composition, photo darkening and modality, as well as their influence on system complexity and power scalability. Recent work on active fibers, pump couplers, mode field adaptors and other fiber-optic components will be presented.

Advanced specialty fiber designs for fiber lasers

Paper 7914-40 of Conference 7914
Date: Wednesday, 26 January 2011
Time: 8:30 AM – 9:00 AM

Author(s): Liang Dong, Clemson Univ. (United States)
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Progress in specialty fibers is the foundation to further breakthroughs in fiber lasers. Recently, we have helped to advance several areas of specialty fibers and would like to review some of these efforts. One area is the development of wide band air-core fibers with an innovative square lattice cladding, leading to significant improvements in bandgaps. Another area is the new development in SBS simulation in optical fibers by incorporating leaky acoustic modes, leading to much improved resolution of SBS gain spectrum in fibers and to new insights on the limit of SBS suppression based on anti-guide acoustic waveguide designs.

Dispersion controlled tellurite air-clad fibers for supercontiuum generations pumped by picosecond and femtosecond fiber lasers respectively

Paper 7934-39 of Conference 7934
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Meisong Liao, Xin Yan, Guanshi Qin, Chitrarekha B. Chaudhari, Takenobu Suzuki, Yasutake Ohishi, Toyota Technological Institute (Japan)
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Tellurite air-clad fibers with 1 μm hexagonal core and different size of holey region were fabricated. The chromatic dispersion of these fibers can be tailored effectively by changing the diameter ratio of holey region to core. One actave flattened SC generation, pumped by a 1064 nm picosecond fiber laser with the pulse energy of several hundred pJ, was demonstrated. Effective second and third harmonic generation was obtained by a 1557 nm femtosecond fiber laser. The dependences of SC generation on the dispersion and nonlinearity were analyzed. Such fibers, with high nonlinearity and controlled dispersion are significant in nonlinear applications.

Performance of low-mode and single-mode optical fibers for high-peak-power 355-nm laser radiation

Paper 7894-36 of Conference 7894
Date: Sunday, 23 January 2011
Time: 2:00 PM – 2:20 PM

Author(s): Georg Hillrichs, Rene Wandschneider, Hochschule Merseburg (Germany); Karl-Friedrich Klein, Cornell P. Gonschior, Fachhochschule Giessen-Friedberg (Germany)
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For applications of fiber guided pulsed UV-laser radiation in biomedical optics or laser spectroscopy which need of a good beam quality low mode or single mode optical fibers are required. We investigated the properties at 355 nm wavelength with peak powers up to 26 GW/cm² . It turns out, that degradation or microstructural damage in the fiber core plays a minor role in long term transmission. Single mode UV laser beam guiding is possible, but the coupling conditions have to be carefully chosen. The upper intensity limit is given by the surface damage threshold. UV beam guiding at high repetition rate, moderate peak power will be compared with that of moderate repetition frequency, high peak power lasers.

Novel evanescent-field-sensor using selectively excited modes in step-index fibers

Paper 7894-37 of Conference 7894
Date: Sunday, 23 January 2011
Time: 2:20 PM – 2:40 PM

Author(s): Karl-Friedrich Klein, Cornell P. Gonschior, Pasma Dahal, Fachhochschule Giessen-Friedberg (Germany); Georg Hillrichs, Hoschshule Merseburg (Germany)
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A novel ATR-sensor with high bending stability for medical and analytical applications will be introduced. Using the selective mode-excitation and new powerful broadband light-sources, the spectral light-guidance of skew modes in different fibers has been studied in more details.

Opto-electrophoretic detection of bio-molecules using conducting chalcogenide glass sensors

Paper 7894-38 of Conference 7894
Date: Sunday, 23 January 2011
Time: 2:40 PM – 3:00 PM

Author(s): Pierre Lucas, Zhiyong Yang, Kelly A. Reynolds, The Univ. of Arizona (United States); Marie-Laure Anne, Bruno Bureau, Univ. de Rennes 1 (France)
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Novel telluride glasses with high electrical conductivity, wide infrared transparency and good resistance to crystallization are used to design an opto-electrophoretic sensor for detection and identification of hazardous microorgansims. The sensor is based on an attenuated total reflectance element made of Ge-As-Te glass that serves as both an optical sensing zone and an electrode for driving the migration of bio-molecules within the evanescent wave of the sensor. An electric field is applied between the optical element and a counter electrode in order to induce the migration of bio-molecules carrying surface charges. The effect of concentration and applied voltage is tested and the migration effect is shown to be reversible upon switching the electric field. The collected signal is of high quality and can be used to identify different bacterial strain through statistical spectral analysis. This technique therefore provides the ability to detect hazardous microorganism with high specificity and high sensitivity in aqueous environments. This has great potential for online monitoring of water quality.

Development of optical fiber head probes for infrared endoscopic medical diagnosis

Paper 7894-40 of Conference 7894
Date: Sunday, 23 January 2011
Time: 3:30 PM – 3:50 PM

Author(s): Marie-Laure Anne, Univ. de Rennes 1 (France); P. Houizot, Univ de Rennes I (France); Bruno Bureau, Univ. de Rennes 1 (France); O. Loréal, INSERM (France); V. Monbet, Univ. de Bretagne Sud (France); C. Boussard-Plédel, J. Lucas, Univ. de Rennes 1 (France)
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Thanks to the development of chalcogenide glass fiber, transmitting light in the infrared range, the infrared spectroscopy can be carried out in situ by Fiber Evanescent Wave Spectroscopy, so-called FEWS. FEWS has proved to be a powerful technology for the study of biomedical samples, in particular for the detection of foodborne pathogens in the food processing industries and for non invasive diagnosis in the medical domain. Recent important progress in the quality and the design of chalcogenide fibers have enabled to obtain optical fiber with a miniaturized head-probe which can be used for endoscopic measurements. FEWS coupled to chemometric methods, such as PCA and PLS, allowed to differentiate between, for instance, healthy and non healthy tissue on human body biological liquid. Thus, FEWS carried out with chalcogenide optical fiber is becoming an efficient tool for physician.

Filters and electro-optic modulators on fiber end-faces

Paper 7913-42 of Conference 7913
Date: Monday, 24 January 2011
Time: 8:00 AM – 8:20 AM

Author(s): Stefan Meister, Dawid Schweda, Marcus Dziedzina, Ronny Juhre, Aws Al-Saadi, Bülent A. Franke, Technische Univ. Berlin (Germany); Bernd Grimm, Sigurd K. Schrader, Technische Fachhochschule Wildau (Germany); Stephanie J. Benight, Denise H. Bale, Ilya Kosilkin, Larry R. Dalton, Univ. of Washington (United States); Hans-Joachim Eichler, Technische Univ. Berlin (Germany)
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A hybrid layer system can be built up to a passive Fabry-Pérot micro-cavity, where alternating dielectric high and low refractive materials are used as mirrors and a highly transparent polymer as the spacer material. Bandwidths of less than 1nm (FWHM) at a wavelength of 1550 nm could be achieved for such micro-cavities on the end-faces of optical fibers. Enhancing the layer system by transparent conductive electrodes and by adding electro-optically active chromophores to the polymeric spacer material, the filter's transmission becomes electrically tunable.

Functional near infrared brain imaging with a brush-fiber optode array to improve study success rates on pediatric subjects with cerebral palsy

Paper 7883G-136 of Conference 7883G
Date: Monday, 24 January 2011
Time: 9:30 AM – 9:50 AM

Author(s): Bilal Khan, The Univ. of Texas at Arlington (United States); Chester Wildey, The Univ. of Texas at Dallas (United States); Fenghua Tian, Mario I. Romero, The Univ. of Texas at Arlington (United States); Mauricio R. Delgado, Nancy J. Clegg, Linsley Smith, Texas Scottish Rite Hospital for Children (United States); Hanli Liu, The Univ. of Texas at Arlington (United States); Duncan L. MacFarlane, The Univ. of Texas at Dallas (United States); George Alexandrakis, The Univ. of Texas at Arlington (United States)
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Neuroimaging techniques are useful to study neuroplastic rearrangements that occur due to dysgenesis, early life injury, or response to treatment in children with cerebral palsy (CP). However, the success rate of radiological imaging studies is low due to motion artifacts. Functional near infrared imaging is robust to motion artifacts but is challenged by scalp-optode optical contact issues. We present novel brush-fiber optodes that overcome scalp contact issues along with computational techniques needed to process such measurements in order to avoid spatial resolution degradation due to larger optode sizes. Validation measurements on children with CP and age-matched controls will be presented.

Three-dimensional functional imaging of lung parenchyma using Fourier-domain optical coherence tomography combined with fluorescence microscopy

Paper 7889-11 of Conference 7889
Date: Monday, 24 January 2011
Time: 11:30 AM – 11:45 AM

Author(s): Maria Gärtner, Peter Cimalla, Lilla Knels M.D., Sven Meissner, Edmund Koch, Dresden Univ. of Technology (Germany)
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Optical coherence tomography (OCT) is widely used in in vivo studies, requiring high resolution and fast three-dimensional imaging. Based on light scattering, it reveals micrometer sized substructures of the samples, allowing the quantification of underlying geometries. Utilizing fluorescent markers, functional information can be obtained from molecular compositions embedded in the investigated object. This research presents the combination of OCT and laser scanning confocal microscopy (LSCM) to investigate structural details in lung tissue. OCT reveals the morphology of the alveoli whereas fluorescence detection, arising from an elastin marker, shows the elastic meshwork of the organs extracellular matrix in three dimensions.

Ex-vivo ultra-high-resolution optical coherence tomography imaging of fine lung structure by use of a high-power Gaussian-like supercontinuum at 0.8-um wavelength

Paper 7893-34 of Conference 7893
Date: Monday, 24 January 2011
Time: 12:10 PM – 12:30 PM

Author(s): Norihiko Nishizawa, Shutaro Ishida, Nagoya Univ. (Japan); Takefumi Ohta, Kazuyoshi Itoh, Osaka Univ. (Japan); Masashi Kitatsuji, Hiroyoshi Ohshima, HOYA Corp. (Japan); Miyoko Matsushima, Tsutomu Kawabe, Nagoya Univ. (Japan)
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Ex vivo cross-sectional imaging of isolated rat lungs was demonstrated using UHR-OCT. A 120 nm-wide, high-power, Gaussian-like supercontinuum was generated at wavelength of 0.8 um region and it was used as the light source in time domain UHR-OCT. An ultrahigh resolution of 2.1 um in tissue was obtained and the achieved sensitivity was 105 dB. The detailed structures of the trachea, visceral pleura, and alveoli were observed clearly. When saline was instilled into the lung, the penetration depth was improved, and clear images of the fine structure of the lung, including alveoli, were observed owing to the index matching effect.


High-power, fused assemblies enabled by advances in fiber-processing technologies

Paper 7914-14 of Conference 7914
Date: Monday, 24 January 2011
Time: 2:40 PM – 3:00 PM

Author(s): Robert Wiley, 3SAE Technologies, Inc. (United States)
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To provide expanded capabilities for fiber laser assembly, a wide-area electrical plasma heat source was used in conjunction with an optimized image analysis method and a flexible alignment system, integrated according to mechatronic principles. High-resolution imaging and vision-based measurement provided feedback to adjust assembly, fusion, and tapering process parameters. The system was used to perform assembly steps including dissimilar-fiber splicing, tapering, bundling, capillary bundling, and fusion of fibers to bulk optic devices up to 10mm diameter. The completed assemblies met the performance targets and exhibited reduced surface contamination compared to assemblies prepared on previously existing equipment.

Optical coherence tomography and confocal fluorescence microscopy as a combined method for studying morphological changes in lung dynamics

Paper 7893-38 of Conference 7893
Date: Monday, 24 January 2011
Time: 4:40 PM – 5:00 PM

Author(s): Maria Gärtner, Peter Cimalla, Lilla Knels M.D., Sven Meissner, Christian Schnabel, Edmund Koch, Technische Univ. Dresden (Germany)
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Acute lung injury (ALI) is a pulmonary disease, leading to hypoxemia, accompanied by reduced lung compliance. The respiratory treatment is strongly connected with ventilator induced lung injury (VILI), introducing further stress to the organ and changes in its elastic performance. This study presents a setup for investigating alveolar compliance depending on volume changes and elastic fiber distributions. Simultaneous acquired optical coherence tomography and confocal fluorescence images allow an entire view into morphological rearrangements during ventilation of an excised lung using continuous positive airway pressure. Further studies will comprise in vivo research for a realistic characterization of lung dynamics.

FBG-nano-cavity on an optical nanofiber

Paper 7913-44 of Conference 7913
Date: Tuesday, 25 January 2011
Time: 2:40 PM – 3:00 PM

Author(s): Kali P. Nayak, The Univ. of Electro-Communications (Japan); Kiyomi Nakajima, National Institute for Materials Science (Japan); Fam L. Kien, The Univ. of Electro-Communications (Japan); Hideki T. Miyazaki, Yoshimasa Sugimoto, National Institute for Materials Science (Japan); Kohzo Hakuta, The Univ. of Electro-Communications (Japan)
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We introduce the fabrication of fiber Bragg gratings (FBGs) on a sub-wavelength diameter silica fiber, an optical nanofiber, by drilling periodic nano-grooves using focused ion beam milling. Using such FBG structures we have realized nanofiber cavity system with a typical finesse of F ~ 20 and the on resonance transmission is ~ 30%. Due to the strong transverse confinement of the field in the guided mode of the nanofiber even with such low finesse strong enhancement of the spontaneous emission of atoms around the nanofiber cavity can be realized. Such "atom + nanofiber cavity" system can become a promising workbench for cavity-QED.

Near-circular pump guides

Paper 7914-107 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): James J. Morehead, Martin H. Muendel, JDSU (United States)
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How nearly circular can a double-clad fiber's pump guide be and still have good absorption in the core? D's and octagons have good absorption but can be hard to cleave and lose power or brightness through splices with circular fibers. For shapes which are nearly circular ray tracing cannot be trusted since the perturbations can be smaller than a transverse wavelength. Using an algorithm well suited to near-circular boundaries, we have computed statistics of core-overlap of the lowest 10,000 modes of many pump-guide shapes. Some with 3% radial modulation have better core-overlap than an octagon.

Performance characterization of new erbium-doped fibers using MCVD nanoparticle doping process

Paper 7914-74 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): David E. Boivin, Alain Pastouret, Ekaterina Burov, Cédric Gonnet, Olivier Cavani, Simon Lempereur, Pierre Sillard, Draka Comteq France (France)
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In 2009, we introduced a new doping concept involving Al2O3/rare-earth nanoparticles (NP) in a MCVD-compatible process. This approach is characterized by the ability to control the rare-earth ion environment independently from the core composition. The NP matrix can therefore be viewed as an optimized sub-micronic amplifying medium for the embedded rare-earth ion. In this paper, we address our most recent work completing our preliminary results and investigating the quenching signatures of new NP designs and their behaviors when incorporated in different core matrices. Their interplay is further analysed by relating this set of measurements to practical EDFA performances.

Radiation effects on fiber amplifiers: design of radiation tolerant Yb/Er-based devices

Paper 7914-98 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Sylvain Girard, Commissariat à l'Énergie Atomique (France); Arnaud Laurent, iXFiber SAS (France); Marilena Vivona, Lab. Hubert Curien (France); Thierry Robin, Benoit Cadier, iXFiber SAS (France); Youcef Ouerdane, Aziz Boukenter, Lab. Hubert Curien (France)
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Rare-earth doped optical fibers have been shown to be very sensitive to radiations. In this paper, we present the results obtained in 2010 on a set of prototype active Erbium/Ytterbium codoped double clad fibers exposed to γ-rays at low dose rate (0.3 rad/s). Previous studies indicated that amplifiers using this type of fiber suffered significant degradation for cumulated dose above 5 krad. We observed, on the contrary, that for an optimized fiber design, the degradation of the Yb/Er fiber amplifier output power can be limited to less than 20% after ~100 krad exposure.

Novel aspects of pulse propagation in photonic crystal fibers

Paper 7946-33 of Conference 7946
Date: Wednesday, 26 January 2011
Time: 8:50 AM – 9:20 AM

Author(s): Sebastian P. Stark, Alexander V. Podlipensky, Philip S. Russell, Max-Planck Institute for the Science of Light (Germany)
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Unconventional wavelength-dependent group velocity dispersion, designed and realised in solid-core photonic crystal fibers (PCFs), can give rise to unusual pulse dynamics. Broad-band supercontinua can be generated in the visible spectral range, with high conversion efficiencies that can be further enhanced by frequent inter-soliton collisions. The high nonlinearity of small-core PCFs, along with a strongly uncompensated pulse chirp, can be used to trigger pulse breakup, leading to the generation of ultrashort THz pulse trains. Experimental and numerical results on the propagation of femtosecond pulses in axially-varying tapered PCF structures will also be discussed.

Selective filling of metals into photonic crystal fibers

Paper 7946-34 of Conference 7946
Date: Wednesday, 26 January 2011
Time: 9:20 AM – 9:40 AM

Author(s): Ron Spittel, Anka Schwuchow, Sven Brückner, Kay Schuster, Jens Kobelke, Hartmut Bartelt, Institut für Photonische Technologien e.V. (Germany)
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We report on our work on the selective filling of holes of various photonic crystal fibers with metals. By applying pressures of almost 200 bar and temperatures of over 1100°C we filled sub-micrometer holes over a length of several centimeters. We analyzed the fibers' transmission spectra and polarization dependent coupling between the fundamental fiber mode and the first higher order surface plasmon polaritons. Furthermore, we measured the near field patterns and studied the influence of the temperature on these resonance wavelengths. The experimental results are compared with semi-analytical calculations of a cylindrical gold wire embedded in fused silica and full vectorial finite element simulations.

Improved laser damage threshold for chalcogenide glasses through surface microstructuring

Paper 7946-35 of Conference 7946
Date: Wednesday, 26 January 2011
Time: 9:40 AM – 10:00 AM

Author(s): Jasbinder Sanghera, U.S. Naval Research Lab. (United States); Catalin Florea, Global Defense Technology & Systems, Inc. (United States); Lynda Busse, Brandon Shaw, Ishwar Aggarwal, U.S. Naval Research Lab. (United States); Douglas Hobbs, Jim Nole, TelAztec LLC (United States)
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We demonstrate improved laser damage threshold of chalcogenide glasses with microstructured surfaces as compared to chalcogenide glasses provided with traditional antireflection coatings. The surface microstructuring is used to reduce Fresnel losses over large bandwidths in As2S3 and As2Se3 glasses and fibers. The treated surfaces show almost of factor of two of improvement in the laser damage threshold when compared with traditional antireflection coatings.

Optically responsive liquid crystal microfibers for display and nondisplay applications

Paper 7955-22 of Conference 7955
Date: Wednesday, 26 January 2011
Time: 2:20 PM – 2:50 PM

Author(s): Ebru A. Buyuktanir, John L. West, Kent State Univ. (United States); Margaret W. Frey, Cornell Univ. (United States)
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We report here the fabrication and characterization of optically-tunable and stimuli-responsive electrospun microfibers endowed with liquid crystal (LC) functionality. The LC microfibers are electrospun from a solution of 4-pentyl-4'-cyanobiphenyl (5CB) and polylactic acid (PLA) in chloroform/acetone solvent. In the electrospinning process, the low molecular weight 5CB phase-separates and self-assembles to form an aligned nematic core within a PLA shell. Most importantly, the orientation of LC domains and, therefore, the optical properties of the 5CB/PLA fibers can be tuned by application of an external electric field. These properties of LC fibers may, in turn, be utilized to fabricate a variety of electro-optical textiles, and ultimately may introduce an entirely new manufacturing process where weaving will reach well beyond the roll-to-roll manufacturing envisioned for the currently emerging flexible displays printed on flexible plastic substrates.

Forward stimulated Brillouin scattering observed in standard highly-nonlinear optical fiber

Paper 7917-34 of Conference 7917
Date: Wednesday, 26 January 2011
Time: 3:00 PM – 3:20 PM

Author(s): Yunhui Zhu, Duke Univ. (United States); Jing Wang, Duke Univ. (United States) and Beijing Jiaotong Univ. (China); Rui Zhang, Daniel J. Gauthier, Duke Univ. (United States)
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We observe forward stimulated Brillouin scattering (FSBS) in a standard highly-nonlinear optical fiber with multiple guided acoustic resonance frequencies that occur between ~30 MHz to beyond the detection limit of 1.3 GHz. The FSBS process results from the scattering of a confined light beam from guided acoustic modes. The tight confinement of light field in the HNLF enhances the light-sound coupling and favors resonances coupling to high frequency acoustic modes. A peak gain of 1.3 is obtained for the resonance at 1.027 GHz when pumped by a 1550-nm-wavelength monochromatic beam of ~ 8 mW.

Compact all-solid-state integrated mid-IR Source

Paper 7917-41 of Conference 7917
Date: Wednesday, 26 January 2011
Time: 5:50 PM – 6:10 PM

Author(s): Igor V. Melnikov, E.L.S. Co. (Russian Federation) and High Q Labs,, Inc. (Canada); Alexander V. Shestakov, E.L.S. Co. (Russian Federation); Anton N. Knigavko, High Q Labs., Inc. (Canada)
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The PPLN slab is combined with a microchip laser, fiber amplifier, and pigtailed narrow-line DFB diode to come up with a compact device that demonstrates stable high-peak power output through near- to mid-IR range at repetition rate up to 40 kHz

Furnace chemical vapor deposition (FCVD) method for special optical fibers fabrication

Paper 7934-43 of Conference 7934
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Alexei A. Malinin, Optogear Oy (Finland); Alexander S. Zlenko, Fiber Optics Research Ctr. (Russian Federation); Ural G. Akhmetshin, Aston Univ. (United Kingdom); Sergei L. Semjonov, Fiber Optics Research Ctr. (Russian Federation)
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The features of the FCVD method of manufacturing preforms for special optical fibers are considered. It is shown that misalignment of substrate silica tube and furnace hole axes has a negative effect on the quality of fabricated preforms, leading to angular and radial asymmetry of the refractive index profile. Ways of getting rid of this and other disadvantages of the FCVD method are described. A comparison of the FCVD and MCVD methods is carried out. It was demonstrated that the FCVD method allows you to manufacture high-quality fiber preforms with good symmetry of the refractive index profile and, therefore, is promising for fabrication of dispersion, dispersion varying and active fibers.

Single-mode regime of 19-cell Yb-doped double-cladding photonic crystal fibers

Paper 7914-67 of Conference 7914
Date: Thursday, 27 January 2011
Time: 5:20 PM – 5:40 PM

Author(s): Enrico Coscelli, Federica Poli, Univ. degli Studi di Parma (Italy); Thomas T. Alkeskjold, NKT Photonics A/S (Denmark); Davide Passaro, Annamaria Cucinotta, Stefano Selleri, Univ. degli Studi di Parma (Italy); Lasse Leick, Jes Broeng, NKT Photonics A/S (Denmark)
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The single-mode regime of 19-cell Yb-doped double-cladding PCFs, successfully exploited for high-power applications due to their large mode area, has been studied. The first higher-order mode cut-off wavelength and overlap on the doped core have been calculated with a finite element based full-vector modal solver. Moreover, its role in the gain competition has been evaluated by applying a spatial and spectral amplifier model. 19-cell double-cladding PCFs with different core diameter and refractive index values have been considered. Simulations have shown the possibility to generalize the results of the single-mode regime by scaling the whole fiber cross-section, including the air-cladding.

Course: High-Power Fiber Sources

Date: Sunday, 23 January 2011
Time: 1:30 PM – 5:30 PM

Instructor(s): Johan Nilsson, Univ. of Southampton (United Kingdom)
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This course describes the principles of high-power fiber lasers and amplifiers, with output powers that can exceed a kilowatt. It reviews current state of the art and research directions of this rapidly advancing field. Fiber technology, pump lasers and input coupling will be addressed. Rare-earth-doped fiber devices including those based on Yb-doped fibers at 1.0 - 1.1 m and the more complicated Er:Yb codoped fibers at 1.5 - 1.6 m and Tm-doped fibers at 2 m will be covered. Devices based on nonlinear scattering phenomena such as stimulated Raman scattering will be considered if time allows. The operating regimes to be treated extend from continuous-wave single-frequency to short pulses. A few key equations will be introduced to find limits and identify critical parameters. For example, pump brightness is a critical parameter for some devices in some regimes but not always. Methods to mitigate limitations in different operating regimes will be discussed. A large core is a critical fiber design feature of high-power fiber lasers, and the potential and limits of this approach will be covered, e.g., as it comes to beam quality.

Course: Interconnection and Splicing of High-Power Optical Fibers

Date: Monday, 24 January 2011
Time: 8:30 AM – 12:30 PM

Instructor(s): Andrew D. Yablon, Interfiber Analysis (United States)
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High-power optical fibers are displacing traditional bulk optical elements in applications such as laser sources, optical amplifiers, and beam delivery systems. However, their high signal or pump powers, large spot sizes or mode areas, and large fiber diameters pose interconnection difficulties including signal loss, mode conversion, polarization crosstalk, reflections, localized heating, end facet damage, and even catastrophic device failure. Various technologies have been developed to address these difficulties including mode field matching technologies, high-power fiber terminations, modal content measurements, and large-diameter fiber cleavers and fusion splicers. This course provides attendees with both conceptual and practical knowledge concerning high-power optical fiber interconnection.

A switchable and tunable dual-wavelength fiber laser based in a polarization-maintaining fiber Bragg grating and a Hi-Bi Sagnac fiber optical loop mirror

Paper 7914-77 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Ricardo I. Alvarez Tamayo, Benemerita Univ. Autonoma de Puebla (Mexico); Manuel Durán Sánchez, Univ. Tecnológica de Puebla (Mexico); Evgeny A. Kuzin, Baldemar Ibarra-Escamilla, Instituto Nacional de Astrofísica, Óptica y Electrónica (Mexico); Olivier Pottiez, Ctr. de Investigaciones en Optica, A.C. (Mexico)
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Operation of a linear cavity dual-wavelength fiber laser using a polarization-maintaining fiber Bragg grating (PM-FBG) generate the refection for the two laser lines. The PM-FBG is also used to tune the laser dual-wavelength. The Hi-Bi Sagnac fiber optical loop mirror (FOLM) adjust the losses inside the cavity. The laser can be operating in wavelength-switch or stable dual-wavelength modes by changes in temperature of the Hi-Bi fiber loop. We also study the laser dual-wavelength operation stability in a wider range of temperature changes through the variation of the amplitude transmission spectrum of FOLM by twist application in the fiber loop.

Phase locking multiple fiber lasers using Talbot self-imaging effect

Paper 7914-106 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Renjie Zhou, Joseph W. Haus, Univ. of Dayton (United States); Baldemar Ibarra-Escamilla, Instituto Nacional de Astrofísica, Óptica y Electrónica (Mexico); Qiwen Zhan, Peter E. Powers, Univ. of Dayton (United States)
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An all fiber based on a self-organized phase-locking fiber laser design is proposed. The output mirror uses a Talbot self-imaging effect in large mode area (LMA) fiber with multiple fiber amplifiers coupled at one end; the LMA fiber length is either a half or full Talbot period. With numerical simulations, the Talbot period distance in a 1D waveguide is found; however, in 2D waveguide the Talbot distance becomes non-periodic. Numerical simulations also show that periodically arranged single mode fibers amplifiers can be coherent combined in the fiber laser cavity. We also investigate how the amplitude and phase variations among fiber amplifiers affect the coupling efficiency and the output far-field pattern.

Smart pillow for heart-rate monitoring using a fiber optic sensor

Paper 7894-1 of Conference 7894
Date: Saturday, 22 January 2011
Time: 8:20 AM – 8:40 AM

Author(s): Zhihao Chen, Ju Teng Teo, Soon Huat Ng, Huiqing Yim, A*STAR Institute for Infocomm Research (Singapore)
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In this paper, we propose and demonstrate a new fiber optic microbending based heart rate sensor for in-bed non-intrusive monitoring. Heart rate measurement is based on ballistocardiography (BCG). The light is modulated through microbending effect when heart beating. The sensing system consists of a light source, a photodetector, a sensor pad, and signal processing unit. The sensor pad is embedded inside a commercially available pillow. An algorithm was developed to extract and report heart rate information of bedded patient. We will also report field trial results by using our prototype system.

Using modalmetric fiber optic sensors to monitor the activity of the heart

Paper 7894-4 of Conference 7894
Date: Saturday, 22 January 2011
Time: 9:00 AM – 9:20 AM

Author(s): Marek Zyczkowski, Military Univ. of Technology (Poland)
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The paper presents the concept of the modalmetric fiber optic sensor system for human psycho-physical activity detection. A fiber optic sensor that utilizes intensity of propagated light to monitor a patient's vital signs such as respiration cardiac activity, blood pressure and body's physical movements. The system can be implemented in embodiments ranging form a low cost in-home to a high end product for in hospital use. We present the laboratory test of comparing their results with the known methods like EKG.

Real-time optical fiber dosimeter probe

Paper 7894-6 of Conference 7894
Date: Saturday, 22 January 2011
Time: 9:40 AM – 10:00 AM

Author(s): Andre Croteau, Serge Caron, François Roy-Moisan, INO (Canada); Alexandra Rink, David A. Jaffray, Princess Margaret Hospital (Canada); Ozzy Mermut, INO (Canada)
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There is a pressing need for a passive fiber-optic dosimeter probe for use in real-time monitoring of radiation dose delivered to clinical radiotherapy patients. A fiber optic probe using radiochromic material has been designed and fabricated based on a thin film of the radiochromic material on the dielectric mirror. Measurements of the net optical density vs. time before, during, and after irradiation at a rate of 500cGy/minute to a total dose of 5Gy were performed. Net OD increased from 0.2 to 2.0 for radiochromic thin film thicknesses of 2 to 20µm, respectively.

Comparison of stone retropulsion for holmium:YAG laser lithotripsy at high-pulse energies versus thulium fiber laser lithotripsy at high-pulse rates

Paper 7883B-44 of Conference 7883B
Date: Saturday, 22 January 2011
Time: 10:50 AM – 11:10 AM

Author(s): Richard Blackmon, The Univ. of North Carolina at Charlotte (United States); Pierce Irby, Carolinas Medical Ctr. (United States); Nathaniel M. Fried, The Univ. of North Carolina at Charlotte (United States)
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Holmium:YAG laser can operate at high pulse energies, but is limited to low pulse rates. Thulium fiber laser is limited to low pulse energies, but can operate at high pulse rates. Stone retropulsion for two different operation modes of Holmium and Thulium fiber lasers are compared. Retropulsion with Holmium laser increases linearly with pulse energy. Retropulsion with Thulium laser is minimal at pulse rates <150 Hz. Thulium laser has lower threshold energy for stone vaporization than Holmium laser, making operation at low pulse energies and high pulse rates a better balance between minimal stone retropulsion and rapid stone vaporization.

Measurement of complex-mode amplitudes in multimode fibers

Paper 7894-9 of Conference 7894
Date: Saturday, 22 January 2011
Time: 11:10 AM – 11:30 AM

Author(s): Bilal A. Alvi, Amber Israr, Saeed Azhar, M. Asif, Sir Syed Univ. of Engineering & Technology (Pakistan)
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This paper described the characterization of mode filling of a multimode optical fiber by the measurement of complex mode amplitudes. The problem of the phase retrieval from single intensity measurement has been solved by using optical analyzers and a modified version of the Gerchberg-Saxton algorithm. The agreement between the absorbed modes and a reconstructed pattern is satisfactory.

Modeling of fiber-based surface plasmon resonance in gold nanorods

Paper 7894-15 of Conference 7894
Date: Saturday, 22 January 2011
Time: 1:40 PM – 2:00 PM

Author(s): Jui-Teng Lin, Ding-Wei Huang, Yu-Hsi Cheng, National Taiwan Univ. (Taiwan)
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This paper presents a normalized transmitted signal (NTS) of a fiber-based sensor using gold nanorods as the plasmon excitation medium of the evanescent wave. For a given cladding RI, the NTS is an increasing (decreasing) function of the core diameter (sensing and core refractive index). The sensitivity is calculated to be about 6-8 (nm/RIU) depending on the sensing refractive index.-Finally, the optimal value of gold aspect ratio is calculated to be about 3.0 for maximum figure of merits defined by the ratio of the refractive index sensitivity and the full width at half maximum. Results based on analytic formulas and finite-difference time-domain (FDTD) are compared.

Double-cladding fiber-based detection system for intravascular mapping of fluorescent molecular probes

Paper 7894-22 of Conference 7894
Date: Saturday, 22 January 2011
Time: 4:40 PM – 5:00 PM

Author(s): R. Nika Razansky, Mathias S. Mueller, Nikolaos C. Deliolanis, Technische Univ. München (Germany); Farouc A. Jaffer M.D., Massachusetts General Hospital (United States); Alexander W. Koch, Vasilis Ntziachristos, Technische Univ. München (Germany)
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Early detection of high-risk coronary atherosclerosis remains an unmet clinical challenge. In this work we improve previously demonstrated near-infrared fluorescence catheter system performance by introducing a novel high resolution sensor. The main challenge of the intravascular sensor is to provide a highly focused spot at an application relevant distance on one hand and a highly efficient collection of emitted light on the other. The sensor automatically rotates and is being pulled-back, while each scanned point is mapped according to the amount of detected fluorescent emission. The resulting map of fluorescence activity in combination with artery morphology associates the atherosclerotic plaques with the inflammation process. This can help to differentiate the atherosclerotic plaques based on their biological activity and identify the ones that prone to rupture and require more medical attention.


Determination of absorber concentration in turbid media free from scattering complications

Paper 7894-23 of Conference 7894
Date: Saturday, 22 January 2011
Time: 5:00 PM – 5:20 PM

Author(s): Can Fang, Yang Liu, David Brokl, Univ. of Pittsburgh Medical Ctr. (United States)
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The in-vivo quantification of absorber concentrations at a consistent tissue depth in biological tissue is important for many biomedical applications. The determination of absorber concentration and probing depth in turbid media is often complicated by their scattering properties. We present a novel design of a fiber-optic probe for assessing absorber concentrations at a constant tissue depth, free from complications in a wide range scattering coefficient and anisotropy factor. We validated the performance of the fiber-optic probe by Monte Carlo simulation and experimental studies. Our results show the promise of accurate determination of absorber concentration in biological tissue.

Small-volume cavity cell using hollow optical fiber for Raman scattering-based gas detection

Paper 7894-25 of Conference 7894
Date: Sunday, 23 January 2011
Time: 8:00 AM – 8:20 AM

Author(s): Yoshinari Okita, Takashi Katagiri, Yuji Matsuura, Tohoku Univ. (Japan)
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The highly sensitive Raman cell based on the hollow optical fiber suitable for the real-time breath analysis is reported. Hollow optical fiber with inner coating of silver is used as a gas cell and a Stokes light collector. A very small cell whose volume is only 0.4 ml or less enables the fast response and real-time measurement of trace gases. To increase the interaction length the cell is arranged in the cavity which consists of a long-pass filter and a high reflective mirror. The cell in the cavity has more than ten times the sensitivity of the cell without cavity.

Reliability of high power diode laser systems based on single emitters

Paper 7918-1 of Conference 7918
Date: Sunday, 23 January 2011
Time: 9:00 AM – 9:20 AM

Author(s): Paul O. Leisher, Ling Bao, Jun Wang, Mike Grimshaw, Mark A. Devito, Aaron Brown, Keith W. Kennedy, Scott R. Karlsen, Jay A. Small, Robert J. Martinsen, Jim Haden, nLIGHT Corp. (United States)
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Diode laser modules based on arrays of single emitters offer a number of advantages over bar-based solutions including enhanced reliability, higher brightness, and lower cost per bright watt. While reports of long lifetimes for single emitter diode laser technology are widespread, the complex relationship between the standalone chip reliability and package-induced failure modes, as well as the impact of built-in redundancy offered by multiple emitters, must also be considered. In this work we present a system-level reliability analysis methodology which includes the interaction of each of the various failure modes in the system.

High-resolution in-vivo targeted imaging of colorectal dysplasia with a LED-based confocal microendoscope

Paper 7893-5 of Conference 7893
Date: Sunday, 23 January 2011
Time: 9:30 AM – 9:50 AM

Author(s): Sakib F. Elahi, Sharon J. Miller, Thomas D. Wang M.D., Univ. of Michigan (United States)
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We demonstrate a LED-based, flexible, fibered microscope that is sufficiently small to pass through the instrument channel of a small animal endoscope for in vivo molecular imaging of the colonic mucosa of mice. The instrument delivers excitation light through a fiber-optic bundle with outer diameter 680 µm, and achieves 0.7 mW of power with a lateral resolution of 4 µm. Independently, FITC-labeled selective and control peptides are applied topically to the mucosa of transgenic mice that spontaneously develop distal colonic adenomas. Using the microendoscope, we found that targeted peptide preferentially binds to adenomas with three-fold greater affinity.

Single-fiber optical imaging device using solid etalon

Paper 7894-30 of Conference 7894
Date: Sunday, 23 January 2011
Time: 9:40 AM – 10:00 AM

Author(s): Hae Jun Ma, Seung Suk Lee, Yong Jin Shin, Eun-Seo Choi, Chosun Univ. (Korea, Republic of)
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We demonstrate optical imaging system, which consists of single fiber as waveguide and non-mechanical scanner. Solid etalon stretches broadband spectrum spatially and each spectral components incident on specimen represents different positions. The combination of solid etalon and swept source provides scanningless optical imaging. In addition, the spectrally distinguished position information is conveyed by single optical fiber. When we apply the proposed scheme to optical imaging system, single optical fiber is good alternative for large field of view imaging. With specially designed etalon, we obtain two-dimensional images of biomedical samples and prove the feasibility of the proposed scheme.

Femto second single optical fiber tweezers enabled two-photon fluorescence excitation of trapped microscopic objects

Paper 7925-4 of Conference 7925
Date: Sunday, 23 January 2011
Time: 10:00 AM – 10:20 AM

Author(s): Yogeshwar N. Mishra, Cochin Univ. of Science & Technology (India); Ninad D. Ingle, Samarendra K. Mohanty, The Univ. of Texas at Arlington (United States)
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Analysis of trapped microscopic objects using fluorescence and Raman spectroscopy is gaining considerable interest. We report on the development of single fiber femto second optical tweezers and its use in two-photon fluorescence excitation (TPE) of trapped fluorescent polystyrene beads. We will present theoretical simulation of femtosecond fiber optical microbeam profiles emerging from the axicon tip and the experimentally observed TPE patterns. The combined use of TPE and optical trapping using single fiber optical tweezers will enable in-depth analysis of non-adherent samples.

Hollow fiber-based Raman tweezers

Paper 7894-32 of Conference 7894
Date: Sunday, 23 January 2011
Time: 10:50 AM – 11:10 AM

Author(s): Takashi Katagiri, Yoshitake Morisaki, Yuji Matsuura, Tohoku Univ. (Japan)
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The optical trapping is useful to suppress random motions of particles when one analyzes a single particle in solutions. Recently, this technique has been combined to Raman spectroscopy and applied for the analysis of bio-particles. In this report, we describe a fiber-optic Raman tweezers for analysis of bio-particles in turbid biological media. The Raman tweezers consists of the single hollow optical fiber and specially designed SrTiO3 lens. The Raman spectra of polystyrene particles dispersed in NaCl aqueous solution were successfully observed. The new design of lens shape for improvement in axial trapping efficiency is examined.

Optimized biasing of pump laser diodes in a highly reliable metrology source for long-duration space missions

Paper 7918-6 of Conference 7918
Date: Sunday, 23 January 2011
Time: 11:10 AM – 11:30 AM

Author(s): Ilya Poberezhskiy, Daniel H. Chang, Hernan Erlig, Jet Propulsion Lab. (United States)
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Optical metrology source reliability on a prolonged space mission is often limited by the reliability of pump laser diodes. We developed a pump module architecture that meets NASA SIM Lite project optical power and reliability requirements by combining the outputs of multiple derated pump diodes in a fiber coupler. We compare the efficiency of several laser diode farm biasing approaches, introducing the instantaneous laser farm aging as an optimization metric. We find that different approaches become preferable depending on pump laser reliability parameter values. Using values typical for COTS 808-nm diodes, we select the optimal biasing approach.

Generation of UV and blue light by using off-axis pumping for fluorescence lifetime spectroscopy

Paper 7925-6 of Conference 7925
Date: Sunday, 23 January 2011
Time: 11:20 AM – 11:40 AM

Author(s): Stefano Taccheo, Swansea Univ. (United Kingdom); Cosimo D'Andrea, Andrea Bassi, Rinaldo Cubeddu, Politecnico di Milano (Italy); Kay Schuster, Jens Kobelke, Klaus W. Morl, IPHT Jena (Germany); Silvia Soria Huguet, Gualtiero Nunzio Conti, Giancarlo C. Righini, Istituto di Fisica Applicata Nello Carrara (Italy)
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We report on fluorescence lifetime spectroscopy in the visible range using light generated by high-order mode propagation in microstructured fiber using a new fiber and a new coupling technique. We extended the wavelength interval generated by supercontinnum generation in a microstructre fiber by coupling the light in the second order mode. We obtained several mW concentrated at around 480 nm and we demonstrated the effectivness of this solution by performing a fluorescence lifetime spectroscopy measurement of a DCM dye dissolved in glycol sample. We also found that peaks down to 350 nm are formed on the continuum spectrum. With this technique light can be efficiently generated in the whole visible range down to 350 nm. An other advantage of this techique is the fiber is very easy to align.

Fiber ring resonator based opto-electronic oscillator phase noise and temperature stability evaluation

Paper 7936-10 of Conference 7936
Date: Sunday, 23 January 2011
Time: 11:30 AM – 11:50 AM

Author(s): Khaldoun Saleh, Aude Bouchier, Pierre-Henri Merrer, Olivier Llopis, Lab. d'Analyse et d'Architecture des Systèmes (France); Gilles Cibiel, Ctr. National d'Études Spatiales (France)
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A 10 GHz microwave optical oscillator is presented. This system is frequency stabilized thanks to an extremely high Q fiber ring resonator (Q = 5 109). The phase noise of this oscillator is measured and discussed thanks to different theoretical approaches. Finally, the thermal stability of the resonator (and the oscillator) is also studied, both theoretically and experimentally. Although the performance of the overall system is still in the range of the performance of the best microwave sources, the high Q factor should open the way to better performance in the future if the noise mechanisms can be understood.

The progress of QD laser in the near IR wavelength region

Paper 7945-13 of Conference 7945
Date: Sunday, 23 January 2011
Time: 12:55 PM – 1:15 PM

Author(s): Daekon Oh, Electronics and Telecommunications Research Institute (Korea, Republic of); Jinsoo Kim, Chonbuk National Univ. (Korea, Republic of); Jinhong Lee, Korea Photonics Technology Institute (Korea, Republic of); Seungui Hong, Cheoluk W. Lee, Wonseok Han, Byung-Seok Choi, Electronics and Telecommunications Research Institute (Korea, Republic of)
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Demand on high quality and new contents in optical internet still requires continuous development of advanced optical components in the point of low cost and high performance. The use of quantum dot structure in the active region of semiconductor optical devices have been shown superior high carrier dynamic and temperature less sensitive properties by some research groups. A 1.5m QD laser on the InP(100) substrate will be demonstrated in detail with the brief review of new achievements of QD optical devices in the near IR wavelength range. Enhanced temperature stability of Fabry-Perot QD laser will be reported compare to the QW laser. Also, 10Gbps direct modulation speed demonstrated with the moderate side mode suppression in the DFB QD laser. Statistic approach for the reproducible formation of quantum dot in the MOCVD and MBE system also will be introduced in this talk.

Fiber coupled diode laser beam parameter product calculation and rule for optimized design

Paper 7918-8 of Conference 7918
Date: Sunday, 23 January 2011
Time: 1:20 PM – 1:40 PM

Author(s): Zuolan Wang, Armin Segref, Tobias P. Koenning, Rajiv Pandey, DILAS Diode Laser, Inc. (United States)
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It is desirable to calculate the 'diagonal' (fiber)BPP, using the BPPs of the fast and slow axes before detailed design and simulation processes. A commonly used expression derived in an earlier work has been found to consistently under-predict the fiber BPP (i.e. better beam quality is predicted than is actually achievable in practice). In this paper, using a simplified model, we provide the proof of the proper calculation of the diagonal component of the fiber BPP using BPPs of the fast and slow axes as input. Using the same simplified model we offer proof that the fiber BPP can be shown to have a minimum (optimal) value if certain rule between the conjugate variables of beam sizes and the numerical apertures along the two axes is obeyed. This optimization is easily calculated before detailed design and it offers valuable insights for the detailed design.

Beam shaping of fiber coupled lasers for plastics processing: concepts for m-shaped beam profiles for optimized scanning processes

Paper 7913-9 of Conference 7913
Date: Sunday, 23 January 2011
Time: 1:30 PM – 1:50 PM

Author(s): Jens Meinschien, Peter Bruns, Alexei S. Mikhailov, Yuri V. Miklyaev, Thomas Mitra, LIMO Lissotschenko Mikrooptik GmbH (Germany)
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Concepts are presented for generating optimized spot geometries, namely a m-shaped radial intensity distribution, for improved plastics processing. Refractive micro lenses and micro lens arrays are key components of these approaches and leading to high efficient and rugged assemblies. Fiber coupled lasers are a versatile tool for plastics processing. Especially for plastics welding, a circular spot is laterally scanned across the work piece and generates a heat impact to create a welding seam. The width and shape of such a welding seam is large influenced by the intensity distribution of the laser spot. The spot size is well defined in these configurations. However, the intensity distribution of the spot is typically not specifically arranged. In most cases, a top hat intensity profile is assumed. This easily leads to nonuniform welding seams due to a parabolic heat impact across the welding seam. This crucial issue can be solved by a specific m-shaped radial intensity distribution.

Course: Fiber Amplifiers

Date: Sunday, 23 January 2011
Time: 1:30 PM – 5:30 PM

Instructor(s): Michel J. F. Digonnet, Stanford Univ. (United States)
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Rare-earth-doped fiber amplifiers have revolutionized the field of optical communications. Amplifiers allow propagating multiple-wavelength light signals modulated at extremely high bit rates along fibers thousands of kilometers long. This functionality has revolutionized the way we communicate, in particular by making the fast Internet an economical reality. This course describes the spectroscopy of rare-earth-doped glass fibers, the principles of the amplifiers based on these fibers, and basic mathematical models describing their operation. It also provides a broad overview of Raman fiber amplifiers. The performance of representative experimental devices is reviewed, including the configuration, pumping schemes, gain, efficiency, gain saturation, noise, and polarization dependence.

Course: Photonic Crystals: A Crash Course, from Bandgaps to Fibers

Date: Sunday, 23 January 2011
Time: 1:30 PM – 5:30 PM

Instructor(s): Steven G. Johnson, Massachusetts Institute of Technology (United States)
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This half-day course will survey basic principles and developments in the field of photonic crystals, nano-structured optical materials that achieve new levels of control over optical phenomena. This leverage over photons is primarily achieved by the photonic band gap: a range of wavelengths in which light cannot propagate within a suitably designed crystal, forming a sort of optical insulator. The course will begin with an introduction to the fundamentals of wave propagation in periodic systems, Bloch's theorem and band diagrams, and from there moves on to the origin of the photonic band gap and its realization in practical structures. After that we will cover a number of topics and applications important for understanding the field and its future. Topics will include: the introduction of intentional defects to create waveguides, cavities, and ideal integrated optical devices in a crystal; exploitation of exotic dispersions for negative-refraction, super-prisms, and super-lensing; the combination of photonic band gaps and conventional index guiding to form easily fabricated hybrid systems (photonic-crystal slabs); the origin and control of losses in hybrid systems; photonic band gap and microstructured optical fibers; and computational approaches to understanding these systems (from brute-force simulation to semi-analytical techniques).

Thermal lensing compensation optics for high power lasers

Paper 7913-11 of Conference 7913
Date: Sunday, 23 January 2011
Time: 2:10 PM – 2:30 PM

Author(s): Michael Scaggs, Neoteric Concepts, LLC (United States); Gilbert J. Haas, Haas Laser Technologies, Inc. (United States)
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Athermalization of focusing objectives is a common technique for optimizing imaging systems in the infrared where thermal effects are a major concern. The athermalization is generally done within the spectrum of interest and not generally applied to a single wavelength. By applying athermalization techniques to a laser system, a significant reduction in thermal lensing of the laser system can be realized. We describe a passive method minimizing thermal lensing of high power lasers.

Wigner distribution function of DBR tapered diode laser

Paper 7918-11 of Conference 7918
Date: Sunday, 23 January 2011
Time: 2:20 PM – 2:40 PM

Author(s): Mirko Uebernickel, Bernd Eppich, Christian Fiebig, Katrin Paschke, Götz Erbert, Ferdinand-Braun-Institut (Germany)
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In this paper, we utilize the concept of the Wigner distribution function (WDF) on distributed-bragg reflector taper lasers (DBR-TPL) up to an output power of 10 W. The WDF allows the derivation of the phase and the intensity distribution just as well the spatial coherence distribution of the laser beam. For a given single mode fiber the theoretical optimum of the coupling efficiency can be obtained by means of a simple overlap integral. Simultaneously, this approach delivers the corresponding beam forming requirements to meet the optimum coupling condition. The coupling efficiencies will be experimentally proofed and compared.

Wavelength and time-multiplexed multi-channel lidar transmitter for topographic mapping mission

Paper 7912-2 of Conference 7912
Date: Sunday, 23 January 2011
Time: 2:30 PM – 2:50 PM

Author(s): Youming Chen, Frank Kimpel, Jean-Luc Fouron, Shantanu Gupta, Fibertek, Inc. (United States); Jeffrey R. Chen, NASA Goddard Space Flight Ctr. (United States)
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We demonstrate an innovative architecture for a nsec pulsed lidar transmitter, scalable to large channel counts, via wavelength- and time-multiplexing in a multi-stage Yb-fiber amplifier. This technology enables lidar systems for topographic mapping missions, requiring much greater spatial coverage and range resolution. We demonstrate prototype hardware, where seed lasers at 1060nm, 1061nm and 1064nm are multiplexed, and 1.3nsec pulse is carved out using LiNbO3 EO-modulators, at repetition rate of 333.3kHz, with equal time interleaving between wavelengths. The multiplexed pulses are amplified to >20W average power, in an optimized 3-stage Yb-fiber amplifier system. We show simple demultiplexing and frequency-doubling of one of the wavelengths (1064nm). High-speed FPGA based control provides for independent and programmable control of the pulse rate, timing trigger, pulsewidth, and the intra-pulse-pattern for improved detection schemes.

Multicolor laser source for STED microscopy

Paper 7905-31 of Conference 7905
Date: Sunday, 23 January 2011
Time: 2:40 PM – 3:00 PM

Author(s): Gregory Keaton, Manuel J. Leonardo, Kiyomi Monro, Mark W. Byer, Manuel Martinez, Mobius Photonics, Inc. (United States)
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We report on a pulsed laser source whose wavelength can be switched between 585 nm, 600 nm, and 615 nm. The pulses are 1 nsec long, the repetition rate is 20 MHz, and the pulse energies are 10 to 40 nJ. The source uses a seed laser and fiber amplifiers to generate pulsed light at 1060 nm. This light undergoes cascaded Raman shifts, and is then converted to the visible by a nonlinear crystal. A dual wavelength Raman laser performs some of the Raman shifts. The final output is suitable for high speed STED microscopy.

Optical-fiber based localized surface plasmon resonance biochemical sensor

Paper 7911-15 of Conference 7911
Date: Sunday, 23 January 2011
Time: 2:40 PM – 3:00 PM

Author(s): Yongbin Lin, Yang Zou, Yuanyao Mo, Jun Namkung, Junpeng Guo, Robert G. Lindquist, The Univ. of Alabama in Huntsville (United States)
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We report the development of a nano-fabrication process to realize periodic arrays of Au nano-dots with subwavelength periodicity on the tips of single mode optical fibers using electron beam lithography (EBL) and reactive ion etching (RIE). The remarkable feature of the resulted optical fiber based localized surface plasmon resonance (LSPR) sensors is the excellent adhesion between the nanodots and fiber end facet. The sensitivity of 196nm/RIU has been demonstrated, measured by testing the fiber tip surface plasmon sensors with different refractive index solutions. The affinity sensing property of the fiber tip LSPR sensor was demonstrated using biotin/streptavidin as receptor and analyte, and the limit of detection (LOD) for was estimated to be 6pM of streptavidin.

Macro-channel cooled, high power, fiber coupled diode lasers exceeding 1.2kW of output power

Paper 7918-13 of Conference 7918
Date: Sunday, 23 January 2011
Time: 3:30 PM – 3:50 PM

Author(s): Tobias P. Koenning, Kimberly R. Alegria, Zuolan Wang, Armin Segref, Dean Spapleton, DILAS Diode Laser, Inc. (United States); Wilhelm Fassbender, Marco Flament, Karsten Rotter, Axel Noeske, Jens Biesenbach, DILAS Diodenlaser GmbH (Germany)
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We report on a new series of fiber coupled diode laser modules exceeding 1.2kW of single wavelength optical power from a 400um / 0.2NA fiber. The units are constructed from passively cooled laser bars as opposed to other comparably powered commercially available modules that use micro-channel heat-sinks. Micro-channel heat sinks require cooling water meeting demanding specifications and are therefore prone to failures due to contamination and increase the overall cost to operate and maintain the laser. Dilas' new series of high power fiber coupled diode lasers are designed to eliminate micro channel coolers and their associated failure mechanisms and cost. Low-smile soldering processes were developed to maximize the brightness available from each diode laser bar. The diode laser brightness is optimally conserved using Dilas' recently developed propriety laser bar stacking geometry and optics. A total of 24 bars are coupled into a single fiber core using a polarization multiplexing scheme. The modular design permits further power scaling through wavelength multiplexing. Other customer critical features such as industrial grade fibers, pilot beams, fiber interlocks and power monitoring are standard features on these modules. The optical design and the beam parameter calculations will be presented to explain the inherit design trade offs. Results for single and dual wavelength modules will be presented.

Delivery of single-mode and multi-mode therapeutic laser light using a single and dual cladding optical fiber for a scanning fiber endoscope

Paper 7894-41 of Conference 7894
Date: Sunday, 23 January 2011
Time: 3:50 PM – 4:10 PM

Author(s): Mark R. Kirshenbaum, Eric J. Seibel, Univ. of Washington (United States)
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The integration of thermal and photodynamic therapy into a scanning fiber endoscope (SFE) has been examined using single-mode and multi-mode configurations of therapeutic high-power 405nm laser light. A single-mode system combines imaging wavelengths and single-mode therapeutic light into the core of an optical fiber to allow therapy at each point in an image. Multi-mode systems keep imaging wavelengths in the core of a single-mode dual cladding optical fiber while therapeutic multi-mode light propagates through the inner cladding. Focusing this light should provide enough power to provide therapy during imaging.

All-fiber optofluidic biosensor

Paper 7888-23 of Conference 7888
Date: Sunday, 23 January 2011
Time: 4:00 PM – 4:15 PM

Author(s): Yunbo Guo, Hao Li, Jing Liu, Karthik Chinna Balareddy, Xudong Fan, Univ. of Michigan (United States)
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A novel all-fiber optofluidic biosensor is presented and investigated for highly-sensitive, label-free biomolecular detection. Two single mode fibers with reflecting surfaces form a simple Fabry-Perot resonator, with a photonic crystal fiber as inherent fluidic channels and a large sensing area platform. The unique configuration makes it able to sensitively detect the substances flowing through the fluidic channels or deposit on the channel surface. It is promising to be developed for multiplexing, highly-sensitive and accurate biomolecular detection.

All-fiber optofluidic biosensor

Paper 7929-23 of Conference 7929
Date: Sunday, 23 January 2011
Time: 4:00 PM – 4:15 PM

Author(s): Yunbo Guo, Hao Li, Jing Liu, Karthik Chinna Balareddy, Xudong Fan, Univ. of Michigan (United States)
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A novel all-fiber optofluidic biosensor is presented and investigated for highly-sensitive, label-free biomolecular detection. Two single mode fibers with reflecting surfaces form a simple Fabry-Perot resonator, with a photonic crystal fiber as inherent fluidic channels and a large sensing area platform. The unique configuration makes it able to sensitively detect the substances flowing through the fluidic channels or deposit on the channel surface. It is promising to be developed for multiplexing, highly-sensitive and accurate biomolecular detection.

Inner-layer-based birefringence measurement of RNFL using PS-OCT

Paper 7885-52 of Conference 7885
Date: Sunday, 23 January 2011
Time: 4:15 PM – 4:30 PM

Author(s): Qiang Wang, Indiana Univ. (United States); Barry Cense, Utsunomiya Univ. (Japan); Omer P. Kocaoglu, Weihua Gao, Ravi S. Jonnal, Sangyeol Lee, Donald T. Miller, Indiana Univ. (United States)
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Change in RNFL birefringence may be a sensitive indicator of retinal tissue health, one that has been suggested to precede clinically detectable vision loss. PS-OCT measures the double pass phase retardation and nerve fiber thickness simultaneously. It can therefore be used to determine the double pass phase retardation per unit depth (DPPR/UD), which is proportional to the birefringence. We propose a new method for post-processing of PS-OCT images and validate the new method and confirm its advantages by comparing it to the traditional slope method.



Dependence of the retinal reflectance on illumination angle and retina location

Paper 7885-53 of Conference 7885
Date: Sunday, 23 January 2011
Time: 4:30 PM – 4:45 PM

Author(s): Weihua Gao, Barry Cense, Qiang Wang, Omer P. Kocaoglu, Ravi S. Jonnal, Sangyeol Lee, Donald T. Miller, Indiana Univ. (United States)
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A research-grade spectral-domain optical coherence tomography system was developed to measure the directional properties of the retina as a function of retinal eccentricity. Particular attention was given the photoreceptor layer (PL), Henle's fiber layer (HFL), and retinal nerve fiber layer (RNFL). The PL reflection was found sensitive to the illumination angle, showing directionalities consistent with the optical Stiles-Crawford effect. Reflections from HFL and RNFL showed dependence not only on the illumination angle, but also the meridian of beam entry in the pupil. A significant variation in apparent thickness of HFL is observed, whereas that of the RNFL shows little.

High repetition rate pulsed 2-micron laser transmitter for CO2 measurement

Paper 7912-6 of Conference 7912
Date: Sunday, 23 January 2011
Time: 4:30 PM – 4:50 PM

Author(s): Upendra N. Singh, Jirong Yu, Yingxin Bai, Mulugeta Petros, NASA Langley Research Ctr. (United States); Songsheng Chen, Science Systems and Applications, Inc. (United States)
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Under the NASA Laser Risk Reduction Program (LRRP), funded by Earth Science Technology Office (ESTO), an efficient, injection seeded, high repetition rate Tm:fiber laser pumped Ho:YLF laser has been developed and operation between 100 Hz to 10 kHz has been demonstrated. The work is underway to develop an efficient, high-repetition-rate, pulsed, 2-micron, coherent Differential Absorption Lidar (DIAL) / Integrated Path Differential Absorption (IPDA) instrument for measuring the atmospheric CO2 profiles (DIAL) and column densities (IPDA) from an airborne platform. In DIAL mode, this instrument will provide the first ever range-resolved, high-precision, remote measurements of the CO2 content of the atmospheric boundary layer (ABL) and lower troposphere.

On the feasibility of photoacoustic microendoscopy using image guide fibers and fiber-laser technology

Paper 7899-24 of Conference 7899
Date: Sunday, 23 January 2011
Time: 4:30 PM – 4:45 PM

Author(s): Shaun M. Kerr, Wei Shi, Roger J. Zemp, Univ. of Alberta (Canada)
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We demonstrate the feasibility of photoacoustic microendoscopy for the first time to our knowledge. The image guide consists of 30,000 individual fibers in a 800-µm bundle, and provides transmission of high optical resolution images in a compact, flexible fiber. Using a fiber laser we produced ~1 ns, 0.13 µJ pulses at 532 nm with a repetition rates up to 600 kHz. The light was coupled to the 1-m long fiber using an objective lens focused on the fiber input, and the beam was scanned across the fiber tip using a high speed mirror galvanometer. Phantom studies indicate 10-20 µm resolution.

Single-crystal YAG fiber optics for the transmission of high energy laser energy

Paper 7894-43 of Conference 7894
Date: Sunday, 23 January 2011
Time: 4:30 PM – 4:50 PM

Author(s): J. A. Harrington, X. Zhu, B. T. Laustsen, Rutgers Univ. (United States); L. G. DeShazer, Lightwave Energenics LLC (United States)
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Single-crystal (SC) fibers have the potential of delivering extremely high laser energies. Sapphire fibers have been the most commonly studied SC fiber and the losses for sapphire fibers have been as low as 0.4 dB/m for a 300-micron core-only fiber at 3 microns. In this study we report on the growth of SC yttrium aluminum garnet Y3Al5O12 (YAG) fibers from undoped SC source rods using the Laser Heated Pedestal Growth (LHPG) technique. The advantage of YAG over sapphire is the slight improvement in IR transmission of YAG. The IR transmission of bulk YAG has been shown to extend to 5-m having an absorption coefficient of 0.6 cm-1. The garnet family of crystals is one of the most commonly used oxide crystal hosts for the lasing ion in high power solid-state lasers, with the most commercially common laser host being YAG. Thus, it is reasonable to assume that YAG fibers will have high laser damage thresholds. The optical losses for 400-micron diameter YAG fibers will be presented. While the current SC YAG fibers do not losses as low as the SC sapphire fibers, they are a good candidate for high energy laser transmission.

A thickness measurement method for biological samples using lensed-fiber sensors

Paper 7894-44 of Conference 7894
Date: Sunday, 23 January 2011
Time: 4:50 PM – 5:10 PM

Author(s): Do-Hyun Kim, Ilko K. Ilev, U.S. Food and Drug Administration (United States); Young-Geun Han, Hanyang Univ. (Korea, Republic of)
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We present non-contact thickness measurement method based on confocal optical fiber sensors. Focusing lens was fabricated at the tip of single-mode fiber and multi-mode fiber using fiber fusion splicer. By using different parameters for splicing, the size and curvature of the melted tip could be precisely controlled. Two lensed-fiber sensors were attached to a mechanical thickness gauge to measure the thickness of soft tissue without contacting their surface. The measurement results from the novel fiber sensor design were compared with the results from mechanical gauges. The results from mechanical gauges produced slightly smaller value due to the compression of soft tissue surface.

Etching enamel for direct bonding with a 1940-nm thulium fiber laser

Paper 7884-19 of Conference 7884
Date: Sunday, 23 January 2011
Time: 4:50 PM – 5:10 PM

Author(s): Ayse S. Kabas Sarp, Murat Gülsoy, Bogaziçi Üniv. (Turkey)
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The aim of this study is determination of the suitable Laser parameters for etching enamel with a 1940- nm Thulium Fiber Laser and keeping that intrapulpal temperature changes below the threshold value. Acid and Laser etched 3 different groups and non-etched one group were debonded with a material testing machine 72 hours after bonding. A Laser etched group showed same debonding force value with acid-etched group and it was over the accepted value for clinical use. Also, a 50% of reduction in time was observed in laser-etched groups. As a result, 1940-nm laser irradiation is a promising method for laser etching.

Live cell STED microscopy with optimized fiber lasers

Paper 7905-36 of Conference 7905
Date: Sunday, 23 January 2011
Time: 4:50 PM – 5:10 PM

Author(s): Sebastian Berning, Brian R. Rankin, Johanna Bückers, Gael Moneron, Stefan W. Hell, Max-Planck-Institut für biophysikalische Chemie (Germany)
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STED super-resolution microscopy offers unique opportunities for experiments with living specimen. Being compatible with common genetically encoded fluorescent markers and offering high image acquisition speeds, the technique has recently attracted significant attention in the life science community. Here we report on live cell STED microscopy using novel fiber laser systems. Being optimized for the temporal and spectral characteristics of specific dyes, these lasers significantly enhance overall imaging performance. By replacing bulky solid-state lasers, they are expected to facilitate the availability of STED microscopy as a standard tool for modern biomedical research.

Double-clad fiber coupler for confocal endomicroscopy

Paper 7893-20 of Conference 7893
Date: Sunday, 23 January 2011
Time: 5:00 PM – 5:20 PM

Author(s): Simon Lemire-Renaud, Mathias Strupler, Fouzi Benboujja, Nicolas Godbout, Caroline Boudoux, Ecole Polytechnique de Montréal (Canada)
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We present a double-clad fiber coupler (DCFC) for use in confocal endomicroscopy to reduce speckle contrast and increase signal collection. The DCFC is made by fusing and tapering two double-clad fibers and allows achromatic transmission of 77% of core illumination (1310±40nm) and collection of 46% of inner cladding diffuse light. To demonstrate its potential, we integrated it in a spectrally encoded confocal microscope. The inner clad images showed a 5.6 fold speckle reduction and 7 fold increase in signal collection, whereas the axial resolution was only lowered by a factor 2.6.

An optical method for the analysis of the exitance diffused by light-transmitting fiber post

Paper 7884-21 of Conference 7884
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Stefano Cattini, Luigi L. Rovati, Univ. degli Studi di Modena e Reggio Emilia (Italy)
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Light-transmitting fiber-posts are known to increase the degree of conversion of light-cured and dual-cured composite resins, thus improving their mechanical properties, solubility, dimensional stability, colour change and biocompatibility. It is known that the curing efficiency of a resin based composite depends on variations in irradiation intensity, time and mode. This study is aimed at providing both a measurement procedure able to easily estimate the exitance generated by illuminated light-transmitting-posts and, the results obtained on nine light-transmitting-posts. The knowledge of these post characteristics will allow choosing the right post and properly setting the light-source power and the exposure-time.

Multiphoton endoscopy based on a mode-filtered single-mode fiber

Paper 7903-95 of Conference 7903
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Sucbei Moon, Gangjun Liu, Zhongping Chen, Beckman Laser Institute and Medical Clinic (United States)
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We present a new low-nonlinearity fiber of mode-filtered single-mode fiber (MF-SMF) for a flexible beam delivery of ultra-short pulses used in the application of multi-photon endoscopy. In our scheme, a few-mode fiber of a relatively large core equips a mode filtering means in the middle of the beam transmission to reject the high-order modes selectively. We demonstrated a scanning catheter two-photon endoscope at the 1.06-um band to show the attractive features of our scheme. Since our method is based on the conventional low-cost fiber technology, the MF-SMF is very easy to handle, especially in fiber splicing and connectorizing.

Target detection and characterization using a hybrid handheld diffusive optical tomography and photo-acoustic tomography system

Paper 7896-97 of Conference 7896
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Patrick D. Kumavor, Andres Aguirre, Chen Xu, John Gamelin, Yasaman Ardeshipour, Behnoosh Tavakoli, Saeid Zanganeh, Umar S. Alqasemi, Quing Zhu, Univ. of Connecticut (United States)
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DOT guided by co-registered ultrasound, MRI, and x-ray has demonstrated great potential to overcome lesion location uncertainty and to improve light quantification accuracy. However, due to the different contrast mechanisms, some lesions may not be detectable by a non-optical modality but yet have high optical contrast. We present a photoacoustic tomography (PAT)-guided diffusive optical tomography (DOT) approach for detection and characterization of targets embedded in turbid media. The PAT light was coupled into two fibers and together with the DOT fibers and ultrasound transducer, was housed in a probe. Measurements of the absorption coefficients of polyvinyl plastisol phantoms yielded values that were 70% accurate.

Thulium fiber laser lithotripsy

Paper 7914-1 of Conference 7914
Date: Monday, 24 January 2011
Time: 8:10 AM – 8:40 AM

Author(s): Nathaniel M. Fried, The Univ. of North Carolina at Charlotte (United States)
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The Thulium Fiber Laser (TFL) wavelength (Wavelength=1908 nm) more closely matches a water absorption peak in tissue than the Holmium:YAG (Ho:YAG) laser (Wavelength=2120 nm), resulting in the TFL being five times more efficient for lithotripsy at low pulse energies. The excellent TFL spatial beam profile also allows coupling of higher laser power into smaller optical fibers for lithotripsy procedures requiring extreme fiber bending, and opens up space through the working port of the flexible endoscope for improved irrigation, visibility, and safety. Development of affordable, high-pulse-energy, long-pulse, Thulium fiber lasers is warranted as an alternative to Holmium:YAG lasers for lithotripsy.

Mode localization, Q-factor, and nonuniformities of a cylinder microresonator: theory and experiment

Paper 7913-21 of Conference 7913
Date: Monday, 24 January 2011
Time: 8:20 AM – 8:40 AM

Author(s): Mikhail Sumetsky, OFS (United States)
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The theory of the resonance propagation of light though a long cylinder microresonator is developed. The effect of localization of whispering gallery modes is described. The shape of the transmission resonances is determined. The Q-factor of these resonances can be as large as the Q-factor of modes in a spheroidal microresonator with the same material loss divided by 2.542. The obtained theoretical results explain the structure of experimentally observed transmission resonances for very uniform optical fibers as well as for fibers with specially introduced radius perturbations. These results are used for extremely accurate testing of the fiber surface quality.

High brightness diode laser module for pump and direct application

Paper 7918-18 of Conference 7918
Date: Monday, 24 January 2011
Time: 8:50 AM – 9:10 AM

Author(s): Dominic Schröder, Alexander Franke, Ekkehard A. Werner, Steffen Wagner, Eckard Deichsel, JENOPTIK Laser GmbH (Germany)
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The industry of laser marking, direct application and solid state laser pumping requires highly reliable and high efficiency laser diodes. The every market has a need for high brightness or power fiber coupled modules. JENOPTIK will show the new 105µm fiber coupled module with an output power of more than 75W and a NA of less than 0.15. The form factor of the module has been decreased without losing stability. The already introduced building block principle has been enhanced to reduce the cost per watt. We will present the new features, power and there wide range of application.

In-vivo optical measurement of activity-dependent fluorescence change in striatum using synaptophluorin mice

Paper 7883G-140 of Conference 7883G
Date: Monday, 24 January 2011
Time: 8:50 AM – 9:10 AM

Author(s): Sang Beom Jun, Guohong Cui, Xin Jin, Michael D. Pham, Christopher Thaler, Steven S. Vogel, National Institutes of Health (United States); Rui Costa, Instituto Gulbenkian de Ciência (Portugal); David M. Lovinger, National Institutes of Health (United States)
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A novel method is proposed to monitor neural activity in synaptophluorin transgenic mice using fiber optics and time-correlated single photon counting. Synaptophluorin is a pH-sensitive EGFP derivative that increases fluorescence upon exocytosis. The optic fibers and a microelectrode array were assembled and implanted into the dorsolateral striatum region of the mice. Anesthesia with isoflurane induced the decrease of photon emission/detection as well as the decreases of electrical neural activity. In behaving animals, fluorescence was transiently increased by an auditory stimulus. These findings indicate that we can use in vivo photometry to measure fluorescence changes that report physiological changes in brain.

Rigorous characterization of silicon nanowires and nanophotonic devices

Paper 7943-16 of Conference 7943
Date: Monday, 24 January 2011
Time: 9:30 AM – 9:50 AM

Author(s): B. M. Azizur Rahman, David Leung, Kejalakshmy Namassivayane, The City Univ. (United Kingdom); A. Law, Harith B. Ahmed, Univ. of Malaya (Malaysia); Ken T. V. Grattan, The City Univ. (United Kingdom)
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High-energy picosecond fiber lasers for coherent Raman microscopy

Paper 7903-28 of Conference 7903
Date: Monday, 24 January 2011
Time: 10:21 AM – 10:41 AM

Author(s): Frank W. Wise, Lingjie Kong, Simon Lefrancois, Dimitre Ouzounov, Cornell Univ. (United States); Changxi Yang, Tsinghua Univ. (China)
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Proliferation of Coherent Raman Microscopy (CRM) will benefit greatly from the development of convenient, inexpensive, compact sources of the required picosecond light pulses. Fiber lasers and amplifiers offer major practical advantages, but the control of adverse nonlinear effects in picosecond fiber sources is a challenge. We will report recent developments in such sources, including the demonstration of a single-mode fiber amplifier that matches the performance of currently-employed solid-state lasers. Work toward the development of all-fiber sources of wavelength-tunable pulses will be described.

On the Raman threshold for passive large mode area fibers

Paper 7914-7 of Conference 7914
Date: Monday, 24 January 2011
Time: 11:10 AM – 11:30 AM

Author(s): Cesar Jauregui-Misas, Jens Limpert, Friedrich-Schiller-Univ. Jena (Germany); Andreas Tünnermann, Fraunhofer-Institut für Angewandte Optik und Feinmechanik (Germany)
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In this work we show that the traditional formula for the Raman threshold in passive fibers is inaccurate for short (several meter long) LMA fibers. Thus some of the widely accepted conclusions about Raman scattering have to be revised accordingly. For example, our calculations show that the Raman threshold intensity becomes higher with larger core areas (as opposed to the general belief that the Raman threshold is always reached for the same intensity). Additionally we provide a revised version of the Raman threshold formula that can be used for LMA fibers.

CARS module for multimodal microscopy

Paper 7903-31 of Conference 7903
Date: Monday, 24 January 2011
Time: 11:13 AM – 11:25 AM

Author(s): Ruben Zadoyan, Tommaso Baldacchini, Chun-Hung Kuo, John L. Carter, David Ocepek, Newport Corp. (United States)
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We describe a stand alone CARS module allowing upgrade of a two-photon microscope with CARS modality. The Stokes beam is generated in a commercially available PCF using fraction of the excitation laser power. We demonstrate functionality of the device on examples of multimodal images of several biological and non-biological samples. We also present results of studies where we used CARS modality to monitor in real time the process of fabrication of nanostructures by two-photon polymerization (CARS movie will be presented).

Synchronized picosecond pulses at two different wavelengths from a compact fiber laser source for Raman microscopy

Paper 7903-32 of Conference 7903
Date: Monday, 24 January 2011
Time: 11:25 AM – 11:45 AM

Author(s): Khanh Q. Kieu, Nasser Peyghambarian, College of Optical Sciences, The Univ. of Arizona (United States)
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We report on the development of a fiber laser system that supplies synchronized picosecond pulses at two different wavelengths suitable for Raman microscopy

Advanced micro-machining applications for low nanosecond high brightness fiber lasers

Paper 7920-7 of Conference 7920
Date: Monday, 24 January 2011
Time: 11:30 AM – 11:50 AM

Author(s): Anthony P. Hoult, IPG Photonics Corp. (United States)
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Master Oscillator Power Fiber Amplifier lasers (MOPFA) lasers have been available for a few years but very short nanosecond pulses (1-10ns) along with low brightness (<1.3) and high repetition rates up to 600kHz has only been achieved recently. These improvements have come about due to the availability of a wide range of standard fiber laser components such as new pump diodes and new fiber oscillators and amplifiers. The work presented here shows that these lasers are capable of the full range of laser micro-machining processes. In addition, new polarisation maintaining pump lasers and a novel second harmonic frequency generation module has led to a low nanosecond green (532nm) laser, and some micro-machining applications are also presented. These new fiber laser designs are capable of far higher pulse repetition rates than those currently available from most conventional lasers and it is shown that this can lead to higher processing speeds.

Suppression of stimulated Brillouin scattering in gain optical fibers through phase-modulation: a time dependent model

Paper 7914-8 of Conference 7914
Date: Monday, 24 January 2011
Time: 11:30 AM – 11:50 AM

Author(s): Clint Zeringue, Iyad A. Dajani, Gerald T. Moore, Air Force Research Lab. (United States)
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We describe a time-dependent model that describes the evolution of stimulated Brillouin scattering (SBS) in Yb-doped fibers under phase-modulated pump conditions. In order to accurately model large frequency modulations, higher-order time derivatives are retained in the phonon equation with the full set of phonon and photon fields solved for numerically. SBS is initiated from noise by using a Langevin term. To validate our simulations, we initially consider sinusoidal single-frequency modulations as a function of modulation amplitude and frequency and show agreement with experimental results. We then investigate effective phase modulation techniques by simulating a broad range of modulation functional forms.

A novel method for increasing the efficiency of 1064nm two tone lasers through heating of the gain fiber

Paper 7914-9 of Conference 7914
Date: Monday, 24 January 2011
Time: 12:50 PM – 1:10 PM

Author(s): Leanne J. Henry, Thomas M. Shay, Air Force Research Lab. (United States); Dane Hult, TREX Enterprises Corp. (United States); Ken Rowland, Boeing LTS Inc. (United States)
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Two tone 1064 nm lasers co-seeded with 1040 nm radiation having cold and room temperature heating zones at fiber lengths optimum for high power have been plagued with lower efficiencies due to residual 1040 nm emission. Our experimental results demonstrate that a reduction in the percentage of 1040 nm radiation in the output of the laser from 45 and 93% with a subsequent increase in efficiency could be obtained by heating the gain fiber to 80C, versus cooling it. SBS suppression through usage of multiple heating stages of 80C and 50C could also be obtained without sacrificing efficiency. The results of these experiments will be presented.

Experimental studies of segmented acoustically tailored photonic crystal fiber

Paper 7914-10 of Conference 7914
Date: Monday, 24 January 2011
Time: 1:10 PM – 1:30 PM

Author(s): Craig A. Robin, Iyad A. Dajani, Furqan L. Chiragh, Air Force Research Lab. (United States)
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We present experimental studies of a PCF possessing a two-segment transverse acoustic profile. The concentrations of the dopants in the two segments were selected such that the Brillouin shifts were sufficiently separated to allow for the introduction of a large thermal gradient. By performing a cutback study in a pump-probe configuration, we estimated the effective Brillouin gain coefficient to be 8.6×10^-12 m/W. A two-step temperature profile was applied leading to four distinct peaks; thus demonstrating further SBS suppression. As a preliminary test and with the entire fiber placed on a cold plate, we built a single-frequency amplifier with a power level approaching 200 W.

20 Gbps optical link with high efficiency 1060 nm VCSEL

Paper 7944-9 of Conference 7944
Date: Monday, 24 January 2011
Time: 1:30 PM – 2:00 PM

Author(s): Jean Benoit Héroux, Masao Tokunari, Shigeru Nakagawa, IBM Japan, Ltd. (Japan)
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We present measurement results of a very low power optical link using GaAs-based 1060 nm VCSEL devices fabricated and provided by Furukawa Electric Co. Ltd. and low cost OM2 fibers up to 100m long. A clear eye opening is observed at 20 Gbps with a 2 mA DC bias, and a bit error ratio below 10E-12 is easily reached. In the next phase of this project a compact, low power CMOS laser driver will be integrated to the system. A transmitter power consumption well below 2 mW/Gbps is expected, and results are promising for data transfer applications in high performance computers.



An integrated time-resolved fluorescence and diffuse reflectance spectroscopy instrument for optical biopsy

Paper 7890-14 of Conference 7890
Date: Monday, 24 January 2011
Time: 1:50 PM – 2:10 PM

Author(s): Zhaojun Nie, Derek Cappon, Joseph E. Hayward, Thomas J. Farrell, Michael S. Patterson, John Provias, Naresh Murty, William McMillan, Qiyin Fang, McMaster Univ. (Canada)
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Combining both diffuse reflectance and time-resolved fluorescence spectroscopy in one optical biopsy instrument allows for the integration of diffuse reflectance, time-resolved, and steady-state spectra for tissue diagnosis. In addition, real-time correction of the fluorescence lifetime and spectrum can be achieved based on in-situ optical property measurements. We designed and developed an integrated, clinically-compatible instrument capable of acquiring time-resolved fluorescence and diffuse reflectance signals simultaneously. The performance of the system including the evaluation of a dual modality, compact fiber-optic probe is discussed. The overall performance of the integrated multi-modality instrument is evaluated using a fluorescence tissue phantom model.

Improved phase modulation for SBS mitigation

Paper 7914-12 of Conference 7914
Date: Monday, 24 January 2011
Time: 1:50 PM – 2:10 PM

Author(s): David M. Brown, Michael L. Dennis, William E. Torruellas, The Johns Hopkins Univ. (United States)
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We have achieved a factor of 2 improvement in the Stimulated-Brillouin-Scattering (SBS) threshold for a 1kW class ytterbium doped fiber amplifier (YDFA) . This improvement has been experimentally demonstrated using a commercial 1 kW fiber amplifier (Nufern), pump limited to 930W, employing an alternative filtering and phase modulation scheme to the single frequency master oscillator (MO) that seeds the amp. Based on our supporting numerical analysis we show that phase modulation resulting in optical spectral broadening can increase or decrease the SBS threshold and can be optimized to improve output power at reduced modulation and optical bandwidths.

Development of an intravascular diagnostic system integrating an IVUS-guided rotational fiber optics catheter for time-resolved fluorescence spectroscopy

Paper 7890-15 of Conference 7890
Date: Monday, 24 January 2011
Time: 2:10 PM – 2:30 PM

Author(s): Hongtao Xie, Julien Bec, Yang Sun, Laura Marcu, Univ. of California, Davis (United States)
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This study describes a bi-modal intravascular technique that combines fast, time-resolved fluorescence spectroscopy (TRFS) to dynamically evaluate atherosclerotic plaque composition of TRFS measurements under intravascular ultrasound (IVUS) guidance. The fiber optic and the IVUS integrated in a 8 Fr catheter sheath are operating independently where the ultrasonic channel can operate "ahead" of the optical channel in a pull-back sequence to guide the TRFS data acquisition. A tissue-mimicking PVA-vessel phantom is used to validate the system for continuous measurement of TRFS data in radial and pull-back. Current results demonstrate the system can operate intravascularly in conditions of blood flow and motion, and acquire the co-registered diagnostic information of plaque biochemical composition and structure.

Fiber optic endomicroscopy for two-photon fluorescence imaging of human gastro-intestinal mucosa

Paper 7890-16 of Conference 7890
Date: Monday, 24 January 2011
Time: 2:30 PM – 2:50 PM

Author(s): Yuying Zhang, Yicong Wu, Jiefeng Xi, Eun Ji Shin, Marcia I. Canto, Xingde Li, The Johns Hopkins Univ. (United States)
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New approach for high-power diode laser modules with homogenized intensity distribution

Paper 7918-29 of Conference 7918
Date: Monday, 24 January 2011
Time: 2:40 PM – 3:00 PM

Author(s): Bernd Köhler, Florian Ahnepohl, Karsten Rotter, Jens Biesenbach, DILAS Diodenlaser GmbH (Germany)
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In the last few years high-power diode laser modules with homogenized intensity distribution have found a growing number of applications, like annealing, hardening and surface illumination. The standard beam shaping concepts in such modules are using an optical waveguide or microoptical lens arrays for homogenization. In this paper we report on a new approach for homogenization of high-power diode laser modules by using linearly arranged fiber bundles to generate homogeneous lines. We present a detailed characterization of a modular diode laser system with 3 kW output power and homogenization by means of a fiber bundle. The dimension of the homogenized line is 200 mm x 2 mm.

Toward single-fiber diffuse optical time-of-flight spectroscopy

Paper 7896-34 of Conference 7896
Date: Monday, 24 January 2011
Time: 2:50 PM – 3:10 PM

Author(s): Erik Alerstam, Tomas Svensson, Stefan Andersson-Engels, Lund Univ. (Sweden); Antonio Pifferi, Lorenzo Spinelli, Davide Contini, Alberto Tosi, Alberto Dalla Mora, Franco Zappa, Politecnico di Milano (Italy)
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In this work we investigate the possibility to perform photon time-of-flight measurements of scattering materials using a setup with a single optical fiber. Using a fast time-gated Single Photon Avalanche Diode (SPAD) in combination with standard Time Correlated Single Photon Counting (TCSPC) electronics the time-of-flight distribution of photons re-entering an optical fiber may be recorded with sufficient dynamic range to differentiate between responses of samples with different optical properties. Preliminary measurement results and Monte Carlo simulations of the setup are presented. Different data evaluation schemes and the possibilities to separate absorption and scattering properties are discussed.

Single-polarization all-solid photonic bandgap fiber incorporating point-by-point Bragg gratings

Paper 7914-15 of Conference 7914
Date: Monday, 24 January 2011
Time: 3:30 PM – 3:50 PM

Author(s): Ryuichiro Goto, Stuart D. Jackson, The Univ. of Sydney (Australia); Robert J. Williams, Nemanja Jovanovic, Graham Marshall, Michael J. Withford, Macquarie Univ. (Australia)
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We demonstrate Point-by-Point (PbP) fiber Bragg grating inscription into the core of a single-polarization all-solid photonic bandgap (PBG) fiber using femtosecond laser pulses. The writing method does not require photosensitivity and a 20-mm-long third-order PbP Bragg grating was written into the non photosensitive, pure silica core of the PBG fiber. The grating strength was 7.5 dB (>80% reflection) at 1064 nm. The 3-dB bandwidth of the reflection was less than 200 pm. A 90-mm-diameter single-turn coiling of the fiber produced a large polarization dependent loss at 1064 nm due to the single-polarization guidance in the fiber, realizing linearly-polarized reflection.

Harmonic generation with fiber MOPAs and solid state lasers: technical challenges, state-of-the-art comparison, and future developments

Paper 7917-18 of Conference 7917
Date: Monday, 24 January 2011
Time: 4:00 PM – 4:20 PM

Author(s): Andrei N. Starodoumov, Norman Hodgson, Coherent, Inc. (United States)
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Fiber MOPAs in the infrared wavelength region offer the advantage of high single mode output powers, independent selection of pulse repetition rates and pulse durations, and access to high repetition rates. Despite these performance advantages, most industrial and scientific applications in the visible and the ultraviolet spectral range are still dominated by solid state lasers. We will give an overview of the technical challenges of harmonic generation in fiber lasers/amplifiers and discuss the state-of-the-art and future of Fiber MOPAs and bulk solid state lasers with harmonic generation.

Harmonic generation with fiber MOPAs and solid state lasers: technical challenges, state-of-the-art comparison, and future developments

Paper 7912-18 of Conference 7912
Date: Monday, 24 January 2011
Time: 4:00 PM – 4:20 PM

Author(s): Andrei N. Starodoumov, Norman Hodgson, Coherent, Inc. (United States)
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Fiber MOPAs in the infrared wavelength region offer the advantage of high single mode output powers, independent selection of pulse repetition rates and pulse durations, and access to high repetition rates. Despite these performance advantages, most industrial and scientific applications in the visible and the ultraviolet spectral range are still dominated by solid state lasers. We will give an overview of the technical challenges of harmonic generation in fiber lasers/amplifiers and discuss the state-of-the-art and future of Fiber MOPAs and bulk solid state lasers with harmonic generation.

Reliability and photodarkening in Tm-doped fibers and lasers

Paper 7914-18 of Conference 7914
Date: Monday, 24 January 2011
Time: 4:30 PM – 5:00 PM

Author(s): Bryce N. Samson, Adrian L. G. Carter, Kanishka Tankala, Nufern (United States)
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In this paper we will review some of the recent Tm-doped fiber laser architectures that are maturing into commercial products. We will review the spectroscopy of 790nm pumping, the maturity and availability of the various key components, including high brightness pump diodes and fiber Bragg gratings, as well as the relevant high efficiency Tm-doped fibers. The role of photo-darkening and other effects on the reliability and life expectancy of these lasers will be reviewed and latest results presented.

Unstable resonators based on gain guiding in photonic bandgap waveguides

Paper 7913-35 of Conference 7913
Date: Monday, 24 January 2011
Time: 4:50 PM – 5:10 PM

Author(s): Tsinghua Her, Lei Zhao, Yue Zhou, Xianyu Ao, Lee W. Casperson, The Univ. of North Carolina at Charlotte (United States)
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Gain guiding in an index-antiguided waveguide can be regarded as a guided-wave unstable resonator due to its intrinsic leaky nature. To facilitate optical pumping, we propose gain guiding in photonic bandgap waveguides to provide simultaneous confinement of laser and pump radiations, in which the signal is gain-guided a low-index core whereas the pump is guided by the photonic bandgap. We theoretically analyze several design configurations of large-core photonic crystal waveguides that support gain guiding to be used for large-mode-area laser amplifiers with single-transverse-mode operation.

Efficient frequency conversion of pulsed microchip and fiber laser radiation in PPSLT

Paper 7912-21 of Conference 7912
Date: Monday, 24 January 2011
Time: 5:00 PM – 5:20 PM

Author(s): Bernd Jungbluth, Sebastian Nyga, Enno Pawlowski, Thomas Fink, Fraunhofer-Institut für Lasertechnik (Germany)
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Extensive studies on frequency doubling with ppSLT crystals are presented. This includes theoretical modeling results and experimental investigations comparing the performance of ppSLT crystals from different providers. Analyses of acceptance parameters and crystal homogeneity are conducted with a pulsed microchip laser. A compact converter module with fiber coupling is designed and tested with the radiation from the microchip laser (6 kW peak, 50 mW average power) and a fiber laser source (25 kW peak, 1 W average power) in comparison. A conversion efficiency of more than 80% and 50% is obtained with the microchip and the fiber laser source respectively.

Efficient frequency conversion of pulsed microchip and fiber laser radiation in PPSLT

Paper 7917-21 of Conference 7917
Date: Monday, 24 January 2011
Time: 5:00 PM – 5:20 PM

Author(s): Bernd Jungbluth, Sebastian Nyga, Enno Pawlowski, Thomas Fink, Fraunhofer-Institut für Lasertechnik (Germany)
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Extensive studies on frequency doubling with ppSLT crystals are presented. This includes theoretical modeling results and experimental investigations comparing the performance of ppSLT crystals from different providers. Analyses of acceptance parameters and crystal homogeneity are conducted with a pulsed microchip laser. A compact converter module with fiber coupling is designed and tested with the radiation from the microchip laser (6 kW peak, 50 mW average power) and a fiber laser source (25 kW peak, 1 W average power) in comparison. A conversion efficiency of more than 80% and 50% is obtained with the microchip and the fiber laser source respectively.

Gamma-radiation-induced photodarkening in ytterbium-doped silica glasses

Paper 7914-19 of Conference 7914
Date: Monday, 24 January 2011
Time: 5:00 PM – 5:30 PM

Author(s): Tomofumi Arai, Kentaro Ichii, Shoji Tanigawa, Munehisa Fujimaki, Fujikura Ltd. (Japan)
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An integrated fluorescence confocal and spectral-domain optical coherence tomography micro-endoscope

Paper 7893-40 of Conference 7893
Date: Monday, 24 January 2011
Time: 5:20 PM – 5:40 PM

Author(s): Houssine Makhlouf, College of Optical Sciences, The Univ. of Arizona (United States); Andrew R. Rouse, Arthur F. Gmitro, The Univ. of Arizona (United States)
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A combined fluorescence confocal and optical coherence tomography (OCT) microendoscope has been constructed to improve the accuracy of diagnosis in optical biopsies by providing complementary en face and cross-sectional image information. The optical train of an existing confocal microendoscope was modified to incorporate spectral domain OCT as an additional mode of operation. This paper reports on the progress made in the implementation of the combined imaging system including: a presentation of the integrated system design, a performance analysis, a discussion of the limitations inherent to using a fiber bundle, and recent imaging results.

100-MHz photoacoustic microscopy system for imaging microscale tumor biology

Paper 7899-153 of Conference 7899
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Timothy S. DeWolf, Janaka C. Ranasinghesagara, Tyler Harrison, Roger J. Zemp, Univ. of Alberta (Canada)
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We present a photoacoustic microscopy system based on a highly focused 100-MHz ultrasound transducer and unique light-delivery optics with spatial resolution of ~35 microns. This system addresses a gap between optical-resolution PAM (OR-PAM) systems with ultra-high-resolution but limited optical penetration, and past PAM systems with resolution defined by the ultrasonic focus. Resolution was quantified by scanning 7-micron carbon fibers in Intralipid. Mechanical scanning was accomplished using a 3-axis stepper-motor system with stepping accuracy and repeatability of <5 microns. Free-space light delivery from a pulsed Optical Parametric Oscillator to dark-field illumination optics was implemented. The system is being used to study the earliest stages of tumor angiogenesis in animal xenograft models at depths beyond those attainable by OR-PAM. Phantom studies and in vivo results will be presented.

Determination of blood types using a chirped-photonic fiber

Paper 7898-46 of Conference 7898
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Anton Malinin, N.G. Chernyshevsky Saratov State Univ. (Russian Federation) and SPE LLC NGT (Russian Federation); Anastasija Zanishevskaja, Julia S. Skibina, N.G. Chernyshevsky Saratov State Univ. (Russian Federation); Igor Silohin, SPE LLC NGT (Russian Federation); Valeriy A. Dubrovskiy, Saratov State Medical Univ. (Russian Federation); Valery V. Tuchin, N.G. Chernyshevsky Saratov State Univ. (Russian Federation); Aleksey Dolmashkin, Saratov State Medical Univ. (Russian Federation)
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The report presents the results of work on definition of human blood groups using chirped photonic fibers (CPF). Method using chirped fiber allows one to obtain a high spectral response for agglutination of blood cells after interaction with clumping serum. The perspectives of using of blood biosensor on the basis of CPFs as sensitive and small-volume blood probe are discussed.

Experimental investigation of wavelength dependence of penetration depth and imaging contrast for ultra-high-resolution optical coherence tomography

Paper 7889-92 of Conference 7889
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Shutaro Ishida, Norihiko Nishizawa, Nagoya Univ. (Japan); Kazuyoshi Itoh, Osaka Univ. (Japan)
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We investigated the wavelength dependence of penetration depth and imaging contrast for biological samples with ultrahigh resolution optical coherence tomography at 0.8 um, 1.3 um, and 1.7 um wavelength region. In each system, we set the adequate optical components using the same composition system. We achieved 3.6 um, 7.9 um, and 6.0 um ultrahigh longitudinal resolutions in air and have more than 90 dB sensitivity. The 1.7 um OCT image had deeper penetration depth and high imaging contrast from other wavelength systems for biological samples. It is expected to be useful for ultrahigh-resolution OCT imaging applications.

Integration of high repetition rate laser with real-time ultrasound for fast photoacoustic signal acquisition

Paper 7899-56 of Conference 7899
Date: Monday, 24 January 2011
Time: 5:30 PM – 5:45 PM

Author(s): Jinjun Xia, Congxian Jia, Univ. of Washington Medical Ctr. (United States); Lingyun Huang, Univ. of Washington (United States); Chi Hyung Seo, Matthew O'Donnell, Univ. of Washington Medical Ctr. (United States)
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Photoacoustic (PA) is very promising in biomedicine application. However, the low repetition rate of the excitation laser limits its application in many fast biological processes, including measurements in the cardiovascular system. In this study, we used a newly available, commercial, high repetition rate compact fiber laser and a multi-channel, real-time ultrasound (US) imaging system to acquire interleaved US/PA data from all channels in an imaging array. A complete 128 element PA array image can be produced from only two firings of a fast laser, and interleaved US/PA images can be reconstructed in real-time at frame rates appropriate for cardiovascular applications.

Real time optical resolution photoacoustic microscopy using fiber-laser technology

Paper 7899-118 of Conference 7899
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Wei Shi, Shaun M. Kerr, Roger J. Zemp, Univ. of Alberta (Canada)
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We are developing a realtime OR-PAM imaging system that uses a high repetition rate diode-pumped Ytterbium pulsed fiber laser and a high speed XY mirror galvanometers. The pulse repetition rate at 532nm output ranges from 20 Hz - 600 kHz. The average power is up to 13 W. In our phantom studies with a ~7.5-µm carbon fiber, we utilized 0.08-µJ ~1-ns pulses at a repetition rate of 150 kHz. Combined with a fast-scanning mirror oscillating at 600 (B-scan) lines per second, we demonstrate a system capable of C-scan imaging at 5 frames per second. The lateral spatial resolution is ~9-µm.

Two dimensional scanning probe using off-axis magnetic force of single solenoid for 3D OCT imaging

Paper 7904-57 of Conference 7904
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Eun Jung Min, Jun Geun Shin, Yuri Kim, Byeong-Ha Lee, Gwangju Institute of Science and Technology (Korea, Republic of)
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We propose a fiber-based two-dimensional scanning probe suitable for three-dimensional optical coherence tomography imaging. The probe is designed based on a single optical lensed fiber cantilever which is loaded with a bead of iron-based ferromagnetic material and actuated with a single miniaturized solenoid aligned perpendicular to the fiber axis. The iron-bead on the fiber is located in the off-axis of solenoid for two-dimensional scanning. By changing input current with time, it was mechanically oscillated in elliptically spiral pattern. With the suggested probe, three-dimensional tomographic images of a coin were successfully obtained with the spectral domain optical coherence tomography equipped with the proposed scanner.

Ultra-high-resolution optical coherence tomography imaging of lung structure using Gaussian-shaped supercontinuum sources

Paper 7889-95 of Conference 7889
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Norihiko Nishizawa, Shutaro Ishida, Nagoya Univ. (Japan); Takefumi Ohta, Kazuyoshi Itoh, Osaka Univ. (Japan); Masashi Kitatsuji, Hiroyoshi Ohshima, HOYA Corp. (Japan); Yoshinori Hasegawa, Miyoko Matsushima, Tsutomu Kawabe, Nagoya Univ. (Japan)
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Ex vivo cross-sectional imaging of isolated lung tissue was demonstrated using ultrahigh-resolution (UHR) optical coherence tomography (OCT). A 120 nm-wide, high-power, Gaussian-like supercontinuum (SC) was generated in the 0.8 um wavelength region and UHR-OCT imaging was demonstrated. An ultrahigh resolution of 2.1 um was obtained in tissue. Using this system, ex vivo UHR-OCT imaging of isolated rat and hamster lungs was demonstrated for the first time. The structures of the trachea, visceral pleura, and alveoli were observed clearly. The index matching with a saline was effective for imaging of alveoli. The wavelength dependence of SC was also examined.

Wavelength agile photoacoustic microscopy with a photonic crystal fiber supercontinuum source

Paper 7899-150 of Conference 7899
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Takashi Buma, Mengyang Liu, Univ. of Delaware (United States)
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Spectroscopic photoacoustic microscopy requires a pulsed nanosecond laser with tunable wavelength, but such lasers are expensive and have poor wavelength switching speed. We are developing a rapidly tunable system based on a high repetition rate supercontinuum source. Our system can produce ten wavelengths per second with access to any wavelength between 575 and 1100 nm. Multiwavelength imaging experiments are performed on phantoms containing four different dyes, which are successfully differentiated using the spectroscopic data. These promising results suggest the potential of our wavelength agile source for functional photoacoustic microscopy.

Fiber-based multi-beam laser Doppler vibrometer for measuring transient vibrations

Paper 7928-7 of Conference 7928
Date: Tuesday, 25 January 2011
Time: 8:20 AM – 8:40 AM

Author(s): Min Guo, Nanyang Technological Univ. (Singapore) and DSO National Labs. (Singapore); Yu Fu, Nanyang Technological Univ. (Singapore); Poh Boon Phua, DSO National Labs. (Singapore)
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The objective is to present a novel fiber-based multi-beam (4×5 laser beam matrix) laser Doppler vibrometer (LDV), using one laser source at 1550nm and one photo-detector. The spatial encoding technique is employed in order to generate transmitted laser beams with different frequency shifts. Heterodyne detection produces a signal which is then demodulated to obtain phase variations of each measurement point on target. This proposed multi-beam LDV is capable of measuring transient events, which is impossible by using a single-beam scanning laser Doppler vibrometer (SLDV). Experimental results on a vibrating aluminium surface help to illustrate this point.

Simultaneous excitation of selective multiple Raman Stokes wavelengths (green-yellow-red) using shaped multi-step pulses from an all-fiber MOPA system

Paper 7914-23 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 9:00 AM – 9:20 AM

Author(s): Dejiao Lin, Peh Siong Teh, Shaif-ul Alam, Kangkang Chen, David J. Richardson, Univ. of Southampton (United Kingdom)
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We report the simultaneous excitation of multiple Raman Stokes lines using multi-step pump pulses and a 250m long fiber gain medium. The frequency doubled output of a single polarization all-fiber Yb-doped MOPA operating at 1060nm was used as the pump source. By adjusting the pump power and the pulse profiles we achieved the simultaneous excitation of green (1st Stokes), yellow (4th Stokes) and red light (6th Stokes) using 3-step pulses or the combination of any two using 2-step pulses. Through the use of pulse shaping we generate sequences of colored pulse and provide dynamic, agile frequency tuning between well-defined wavelengths.


Ultra-thin 350-micrometer diameter high-resolution fiber optic confocal probe

Paper 7891-17 of Conference 7891
Date: Tuesday, 25 January 2011
Time: 9:00 AM – 9:20 AM

Author(s): Dirk Lorenser, Rajesh S. Pillai, Robert A. McLaughlin, David D. Sampson, The Univ. of Western Australia (Australia)
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The miniaturization of high-numerical-aperture microscope objectives down to hypodermic needle dimensions would enable interstitial in-vivo imaging of deep tissue with confocal microscopy. However, this poses significant challenges in terms of optical design and fabrication. We demonstrate a 350-µm diameter probe using graded-index (GRIN) optics with a lateral resolution of 1 µm and an axial resolution of 11 µm. To the best of our knowledge this is the highest resolution reported for a confocal probe of this size. We discuss the optical design of the objective, and present the experimental characterization of the fabricated probe in a prototype scanning setup.

All-fiber mid-IR supercontinuum source from 1.5 to 5 μm

Paper 7914-24 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 9:20 AM – 9:40 AM

Author(s): L. Brandon Shaw, Rafael Gattass, Jasbinder S. Sanghera, Ishwar Aggarwal, U.S. Naval Research Lab. (United States)
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An all-fiber supercontinuum source extending from 1.5 to 5 µm has been demonstrated in single mode step index As2S3 fiber using a Raman shifted erbium doped mode-locked silica fiber laser pump source. 140 mW broadband power was demonstrated with a spectral intensity variation of 10 dB from 1.9 to 4.4 µm and 20 dB from 1.65 to 4.78 µm.

Feasibility of minimally invasive fiber-based evaluation of chondrodystrophoid canine intervertebral discs by light absorption and scattering spectroscopy

Paper 7895-6 of Conference 7895
Date: Tuesday, 25 January 2011
Time: 9:40 AM – 10:00 AM

Author(s): Yuanyuan Jiang, Kelci L. McKeirnan, Kenneth E. Bartels, Daqing Piao, Oklahoma State Univ. (United States)
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The study is to investigate the feasibility of a fiber-needle based spectral analysis of the chemical compositions involved in the chondrodystrophoid condition of canine intervertebral disc. This condition is associated with loss of water, and deposit of calcified mineral in the nucleus pulposus of the disc. The unique anatomy imposes a "shallow-and-small-slab" light sensing geometry. A single-fiber sensor is built into a 20 gauge myelographioc spinal needle, and a tungsten light source is combined with a 940nm light-emitting-diode for spectral illumination covering VIS/NIR with improved sensitivity to water. The reflectance spectra are processed to estimate the scattering and absorption compositions.

High-power all fiber picosecond sources from IR to UV

Paper 7914-25 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 9:40 AM – 10:00 AM

Author(s): Simonette Pierrot, Julien Saby, François Salin, Benjamin Cocquelin, EOLITE Systems (France)
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We have developed several high power picosecond sources using rod-type fiber systems. We will show that a very simple architecture can produce average power over 90 W @ 1030 nm, 45 W@ 515 nm and 20 W @ 343 nm, with pulse repetition rates ranging from 200 kHz to 80 MHz. Particular emphasis will be given on the control of non-linear effects in the fiber without relying on CPA.

Resonantly cladding-pumped Yb-free Er-doped LMA fiber lasers: power scaling and efficiency improvement

Paper 7914-26 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 10:00 AM – 10:20 AM

Author(s): Jun Zhang, Viktor Fromzel, Tigran Sanamyan, Mark Dubinskii, U.S. Army Research Lab. (United States)
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Highly scalable, efficient, low quantum defect laser operation of the resonantly cladding-pumped Yb-free Er-doped laser based on the COTS LMA fiber has been demonstrated. Our experiments were the next step in power and efficiency scaling of this type of laser. Single transverse mode operation with over 88 W of output at 1590-nm was obtained with 1532-nm pumping. Maximum optical-to-optical efficiency obtained in these experiments is ~69%. This result presents, to the best of our knowledge, the highest power ever reported from Yb-free Er-doped LMA fiber laser, as well as the highest efficiency ever reported for any cladding-pumped Er-doped laser.

Liquid crystal photonic crystal fibers and their applications (Keynote Presentation)

Paper 7955-33 of Conference 7955
Date: Tuesday, 25 January 2011
Time: 10:30 AM – 11:10 AM

Author(s): Tomasz R. Wolinski, Warsaw Univ. of Technology (Poland)
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Characterization of high index microsphere resonators in fiber-integrated microfluidic platforms

Paper 7913-39 of Conference 7913
Date: Tuesday, 25 January 2011
Time: 11:00 AM – 11:20 AM

Author(s): Oleksiy Svitelskiy, Dongning Sun, Arash Darafsheh, Vasily N. Astratov, The Univ. of North Carolina at Charlotte (United States)
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We investigate high-Q microsphere resonators with whispering gallery modes using a tapered optical microfiber immersed in a liquid inside a microfluidic platform. The strength of the coupling between the cavity and the microfiber taper is shown to depend on the contact position of the microsphere along the taper and on the refractive index contrast between the microsphere and the liquid environment. We demonstrate that barium titanate glass beads with index around 1.9 are promising candidates for developing sensor and optomechanical applications of such resonator systems.

Coherent phase locking of high-pulse energy fiber amplifiers

Paper 7914-28 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 11:10 AM – 11:40 AM

Author(s): Stephen Palese, Eric Cheung, Fabio Di Teodoro, Mark E. Weber, Northrop Grumman Aerospace Systems (United States)
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The results for active coherent phase locking of high peak power (2 mJ/pulse @ 1ns FWHM) in large mode area 100 um photonic crystal fiber rod amplifiers are discussed. This talk provides an overview of the fundamental sources of non-linear chirp that complicates active phasing for pulsed architectures, phase compensation schemes to correct for both interpulse and intrapulse distortions and factors that limit amplifier number scalabilty. The phase noise spectrum relative to an ultra-stable CW reference source and phasing fidelity measurements for pulse energies up to 2 mJ/pulse (25 KHz repetition rates @1 ns FWHM) will be presented.

High density active optical cable: from a new concept to a prototype

Paper 7944-20 of Conference 7944
Date: Tuesday, 25 January 2011
Time: 11:50 AM – 12:10 PM

Author(s): Denis Wohlfeld, Frank Lemke, Holger Froening, Sven Schenk, Ulrich Bruening, Ruprecht-Karls-Univ. Heidelberg (Germany)
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Active Optical Cables provide very high bandwidth over distances up to several hundred meters and are of special interest in high performance computing. The development of a fiber to VCSEL/PD coupling method and results of a 12x AOC prototype are presented. The fiber coupling concept is based on a direct replication of integrated fiber coupling structures on top of VCSEL/PD arrays. Electrical optical conversion is realized inside a high density mini-HT connector requiring less than half the size of a CXP - AOC. Thus placement of six 12x connectors on a standard PCI-E board, currently 120 Gbps per link, was achieved.

Coherent combining of low-peak-power pulsed fiber amplifiers with 80-ns pulse duration

Paper 7914-31 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 12:20 PM – 12:40 PM

Author(s): Pierre Bourdon, Kevin Cadoret, Laurent Lombard, Adrian Azarian, Guillaume Canat, Baya Bennaï, Didier Goular, Véronique Jolivet, ONERA (France); Yves Jaouën, Telecom ParisTech (France); Olivier Vasseur, ONERA (France)
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We investigate the feasibility of low-peak-power pulsed fiber amplifier coherent combining. Therefore, we characterize phase fluctuations in low-peak-power pulsed fiber amplifiers using two different interferometric techniques. These measurements reveal that for low peak-powers, phase fluctuations remain moderate during the pulses. Noticeable phase fluctuations occurring between the pulses can be perfectly controlled using classical continuous-wave-efficient combining techniques. Results of such realization combining two low-peak-power pulsed fiber amplifiers, using classical frequency-tagging coherent combining techniques, are presented. Phase difference measurement is performed between pulses using a small signal leak from the common master oscillator.

Lifetime and energy-transfer in rare-earth highly-doped glasses for 2 micron lasers

Paper 7934-7 of Conference 7934
Date: Tuesday, 25 January 2011
Time: 2:00 PM – 2:20 PM

Author(s): Stefano Taccheo, Masud A. Taher, Swansea Univ. (United Kingdom); Hrvoje Gebavi, Joris Lousteau, Daniel Milanese, Politecnico di Torino (Italy); Nasser Peyghambarian, College of Optical Sciences, The Univ. of Arizona (United States)
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Highly-doped glasses will be extremely useful for compact 2-micron lasers. In order to evaluate laser performances we made a set of tellurite glasses with Tm concentration ranging from 0.36wt% to 10wt% (2.2 10E21 ion/cm3). We measurede the lifetime of energy level involved in the pumping and lasing processes and we inferred the energy-transfer parameters. We also assessed the impact of radiation self-trapping on lifetime and emission spectra measurement.

A monolithic thulium doped single mode fiber laser with 1.5ns pulsewidth and 8kW peak power

Paper 7914-32 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 2:10 PM – 2:30 PM

Author(s): Jianwu Ding, Bryce Sampson, Chiachi Wang, Kanishka Tankala, Adrian L. G. Carter, Nufern (United States)
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Here we report a compact monolithic 2000nm pulsed laser with a single spatial mode output, ~1.5ns pulsewidth, 8kW peak power and >200mW average power at 20 kHz repetition rate. The gain-switched 2000nm laser was core pumped by a high peak power pulsed 1550nm laser. When the input pulse energy of the 20 kHz pump pulses was sufficient enough to saturate the Thulium fiber, a stable 20 kHz pulse train was observed with linewidth of 0.05nm. This compact pulsed 2um laser, to the authors' limited knowledge, represents the first Thulium doped fiber laser with 8kW peak power and several ns pulsewidth.

Wavefront sensing and adaptive control in phased array of fiber collimators

Paper 7924-14 of Conference 7924
Date: Tuesday, 25 January 2011
Time: 2:20 PM – 2:40 PM

Author(s): Svetlana L. Lachinova, Univ. of Maryland, College Park (United States); Mikhail A. Vorontsov, Univ. of Dayton (United States)
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We introduce a new wavefront control concept for coherent combining of multiple laser beams that are generated by an array of fiber collimators (subapertures) and transmitted to a target plane through atmospheric turbulence. The target-plane beam combining requires compensation of optical path differences (piston phases) originated along the propagation path between the transmitter aperture and the target. In the proposed adaptive control technique, sensing of the piston phases, as well as higher order aberrations, is performed through local (on subaperture) measurements of average wavefront tilts from the received (backscattered) wave. Results of analysis and numerical simulations are presented.

RF-modulated pulsed fiber-optic lidar transmitter for improved underwater imaging and communications

Paper 7924-17 of Conference 7924
Date: Tuesday, 25 January 2011
Time: 3:20 PM – 3:40 PM

Author(s): Frank Kimpel, Youming Chen, Bruce McIntosh, Jean-Luc Fouron, Shantanu Gupta, Fibertek, Inc. (United States)
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5W green (532nm) fiber laser transmitter with programmable RF(GHz)-modulated pulse packet is demonstrated, for underwater imaging and communication application in littoral waters. This is based on a multi-stage Yb-fiber-amplifier system, where the pulse formation is achieved via high-speed FPGA-based control of the seed laser drive and modulator drive and bias-control. In addition to time-gating of the few nsec pulse-packet, the high frequency content of transmitted pulse reduces the effect of volume backscatter in turbid waters, thereby enhancing the image contrast. Initial testing of this lidar using a PMT receiver, through 15m of simulated turbid waters, has demonstrated enhanced imaging capability, as well as that for high bit-rate communication.

All-fiber based amplification of 40 ps pulses from a gain-switched laser diode

Paper 7912-36 of Conference 7912
Date: Tuesday, 25 January 2011
Time: 4:00 PM – 4:20 PM

Author(s): Sebastian Kanzelmeyer, Hakan Sayinc, Thomas Theeg, Maik Frede, Jörg Neumann, Dietmar Kracht, Laser Zentrum Hannover e.V. (Germany)
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Amplification of a gain-switched laser diode is demonstrated in an all-fiber based setup. The fraction of the background amplified spontaneous emission between two consecutive pulses was investigated in the time domain. A maximum pulse energy of 13 µJ at a repetition rate of 1 MHz and a pulse duration of 40 ps was extracted, corresponding to a peak power of 270 KW. To the best of our knowledge, this is the highest extracted pulse energy from a laser system seeded by a gain-switched laser diode. Temporal pulse deformation due to intrapulse Raman scattering was observed in the reported system.

All-fiber based amplification of 40 ps pulses from a gain-switched laser diode

Paper 7914-36 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 4:00 PM – 4:20 PM

Author(s): Sebastian Kanzelmeyer, Hakan Sayinc, Thomas Theeg, Maik Frede, Jörg Neumann, Dietmar Kracht, Laser Zentrum Hannover e.V. (Germany)
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Amplification of a gain-switched laser diode is demonstrated in an all-fiber based setup. The fraction of the background amplified spontaneous emission between two consecutive pulses was investigated in the time domain. A maximum pulse energy of 13 µJ at a repetition rate of 1 MHz and a pulse duration of 40 ps was extracted, corresponding to a peak power of 270 KW. To the best of our knowledge, this is the highest extracted pulse energy from a laser system seeded by a gain-switched laser diode. Temporal pulse deformation due to intrapulse Raman scattering was observed in the reported system.

Atmospheric absorption spectroscopy using Tm:fiber ASE source around 2 micron

Paper 7924-20 of Conference 7924
Date: Tuesday, 25 January 2011
Time: 4:40 PM – 5:00 PM

Author(s): Pankaj Kadwani, CREOL, The College of Optics and Photonics, Univ. of Central Florida (United States); Jeffrey Chia, College of Optical Sciences, The Univ. of Arizona (United States); Robert A. Sims, Christina Willis, Clemence Jollivet Salvin, Lawrence Shah, CREOL, The College of Optics and Photonics, Univ. of Central Florida (United States); Dennis Killinger, Univ. of South Florida (United States); Martin C. Richardson, CREOL, The College of Optics and Photonics, Univ. of Central Florida (United States)
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We investigate atmospheric absorption using a thulium doped silica fiber ASE source. This source is based on a ~2-m long Tm:fiber and generates a broadband spectrum from 1880 nm to 2040 nm. We measure the transmission through a 1-m long propagation cell for several gases from ~1x10^-3 torr to atmospheric pressure, and compare to High Resolution Transmission simulation. This facility is ideal for controlled short-range experiments to calibrate long-range propagation conditions.

The performance of all-optical switching based on fiber Bragg grating

Paper 7933-31 of Conference 7933
Date: Tuesday, 25 January 2011
Time: 4:50 PM – 5:10 PM

Author(s): Wenxuan Yang, Zhigang Zang, Harbin Institute of Technology (China)
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The optical performances of the Fiber Bragg Gratings (FBG) all-optical switches are studied under the cases of the cross-phase modulation (XPM). The expressions of the switching power threshold in the different detuning range are given. The influence of parameter about different detuning and couple ratio to the threshold of switching power and extinction ratio of devices is also studied. It is may be usful for designing the all-optiacl switches based on FBG.

High-power diode pumped crystal fiber amplifier for passively Q-switched Nd:YAG microlaser

Paper 7912-38 of Conference 7912
Date: Tuesday, 25 January 2011
Time: 5:00 PM – 5:20 PM

Author(s): Igor Martial, Lab. Charles Fabry (France) and FiberCryst (France); François Balembois, Lab. Charles Fabry (France); Julien Didierjean, FiberCryst (France); Patrick Georges, Lab. Charles Fabry (France)
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The Master Oscillator Power Amplifier configuration is very useful to extend laser performance of passively Q-switched Nd:doped microlasers in view of material processing applications. Different configurations and gain media have already been used in the past few years and crystal fibers emerged as an interesting new laser medium bridging the gap between the bulk lasers and the fiber lasers. In this work, a passively Q-switched Nd:YAG microchip laser generating 80 µJ, 500 ps pulses with a repetition rate of 1 kHz was efficiently amplified by a simple pass, diode-pumped Nd:YAG crystal fiber amplifier to achieve 1.2 mJ pulses.

High-power diode pumped crystal fiber amplifier for passively Q-switched Nd:YAG microlaser

Paper 7914-38 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 5:00 PM – 5:20 PM

Author(s): Igor Martial, Lab. Charles Fabry (France) and FiberCryst (France); François Balembois, Lab. Charles Fabry (France); Julien Didierjean, FiberCryst (France); Patrick Georges, Lab. Charles Fabry (France)
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The Master Oscillator Power Amplifier configuration is very useful to extend laser performance of passively Q-switched Nd:doped microlasers in view of material processing applications. Different configurations and gain media have already been used in the past few years and crystal fibers emerged as an interesting new laser medium bridging the gap between the bulk lasers and the fiber lasers. In this work, a passively Q-switched Nd:YAG microchip laser generating 80 µJ, 500 ps pulses with a repetition rate of 1 kHz was efficiently amplified by a simple pass, diode-pumped Nd:YAG crystal fiber amplifier to achieve 1.2 mJ pulses.

60 fs pulses from an all-fiber dissipative soliton erbium oscillator

Paper 7914-86 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Nikolai B. Chichkov, Katharina Hausmann, Dieter Wandt, Laser Zentrum Hannover e.V. (Germany) and QUEST - Ctr. for Quantum Engineering and Space-Time Research (Germany); Uwe Morgner, Leibniz Univ. Hannover (Germany) and Laser Zentrum Hannover e.V. (Germany) and QUEST - Ctr. for Quantum Engineering and Space-Time Research (Germany); Jörg Neumann, Laser Zentrum Hannover e.V. (Germany) and QUEST - Ctr. for Quantum Engineering and Space-Time Research (Germany); Dietmar Kracht, Laser Zentrum Hannover e.V. (Germany) and QUES - Ctr. for Quantum Engineering and Space-Time Research (Germany)
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We present a mode-locked all-fiber erbium oscillator with net-normal dispersion. The oscillator consists of a ring resonator with a total dispersion of 0.023 ps2 and is mode-locked by use of nonlinear polarization rotation and a spectral filter with a bandwidth of 70 nm. The normal resonator dispersion and the spectral filter lead to dissipative soliton operation of the oscillator. The oscillator generates output pulse energies of 1.6 nJ at a repetition rate of 104 MHz. The output pulses cover the spectral range from 1490 nm to 1600 nm at -10 dB and are compressed to a duration of 60 fs.

All-fiber 7x1 signal combiner for incoherent laser beam combining

Paper 7914-93 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Danny Noordegraaf, Martin D. Maack, Peter M. W. Skovgaard, Jeppe Johansen, NKT Photonics A/S (Denmark); Mats Blomqvist, Optoskand AB (Sweden); Jesper Laegsgaard, Technical Univ. of Denmark (Denmark)
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We demonstrate an all-fiber 7x1 signal combiner for incoherent laser beam combining. This is a key component in reaching several kW of stabile laser output power. The combiner couples the output from 7 single-mode (SM) fiber lasers into a single multi-mode (MM) fiber. The input signal fibers have a core diameter of 17 µm and the output MM fiber has a core diameter of 100 µm. In the tapered section light couples out of the SM fibers and is caught by an F-doped cladding. The numerical aperture of the output light is <0.06 and the M2 value is measured to be 6.5. These values are approaching the theoretical limit, when brightness conservation is assumed. The combiner is expected to reach several kW of average output power.

Analysis of single frequency Raman amplifier for guide star application

Paper 7917-68 of Conference 7917
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Iyad A. Dajani, Christopher L. Vergien, Clint Zeringue, Air Force Research Lab. (United States)
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We analyze the scalability of amplifying a single frequency diode laser operating at 1178nm through the utilization of a Raman fiber amplifier. A model that accounts for stimulated Raman scattering (SRS), stimulated Brillouin scattering (SBS) and amplifier noise is developed. In order to mitigate the SBS process, we employ a multi-step temperature distribution that is spatially optimized along the length of fiber. We also consider the feasibility of generating the D2a and D2b lines in a sodium beacon from a Raman amplifier by examining four-wave mixing. We provide preliminary results from our SBS studies on an in-house built amplifier.

Arbitrarily-shaped bursts of picosecond pulses from a fiber laser source for high-throughput applications

Paper 7914-71 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Louis Desbiens, Mathieu Drolet, Vincent Roy, Marco M. Sisto, Yves Taillon, INO (Canada)
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We have developed a high-power fiber laser emitting arbitrarily-shaped bursts of picoseconds pulses at 20 W of average output power. Burst duration can be varied from 2.5 ns to 80 ns. The burst repetition rate is externally triggered and can be varied from 100 kHz to 1 MHz. The single pulse duration is 60 ps and the repetition rate within a burst is 1.8 GHz. The output beam is linearly polarized (PER > 20 dB) and its M2 value is smaller than 1.15. The laser source has a tunable central wavelength around 1064 nm and a spectral linewidth compatible with frequency conversion. A conversion efficiency higher than 60% has been obtained at 10 W of 1064-nm output power.

Breaking the symmetry: enhanced transversal mode discrimination in large pitch photonic crystal fibers

Paper 7914-92 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Fabian Stutzki, Florian Jansen, Cesar Jauregui, Friedrich-Schiller-Univ. Jena (Germany); Jens Limpert, Friedrich-Schiller-Univ. Jena (Germany) and Helmholtz-Institut Jena (Germany); Andreas Tünnermann, Fraunhofer-Institut für Angewandte Optik und Feinmechanik (Germany)
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We study the influence of different non-hexagonal geometries on the mode discrimination of Large Pitch Photonic Crystal Fibers (LPF). Recent simulations and experiments with hexagonal LPFs have shown the high potential for mode field area scaling offered by these fibers. LPFs maintain a robust single mode operation even under strong x-y-coupling misalignment resulting in an excellent pointing stability. Nevertheless, the mode discrimination is consistently reduced for large mode areas. Thus, in this work we propose asymmetric designs to enhance the transversal mode discrimination dramatically. This new design can enable intrinsic single mode operation even at mode field diameters well beyond 100µm.



Coherent coupling of spectrally broadband fiber laser channels

Paper 7914-100 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Anatoliy I. Khizhnyak, Vladimir B. Markov, James M. Kilpatrick, Ivan Tomov, MetroLaser, Inc. (United States)
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Fiber lasers (FL) are the most effective source of a high-power radiation. The FL's output power though high, is limited by thermal and nonlinear effects. Further increase in their output power can be achieved through coherent combining of multiple channels. This presentation discusses a novel approach in laser beam combining. The proposed technique is based on the feature of a stable-configuration cavity to automatically match the wave-front of the lasing modes to the output coupler over the entire lasing spectral bandwidth. Another important feature of the proposed scheme is in its ability to match the outputs of the individual FLs to a corresponding high-order cavity mode. The phase corrector is then used to transform this high-order mode in the diffraction-limited output beam. The proposed method enables coupling multiple broadband channels with no need in an external control of each channel. Data on 4-channels transform in the Hermit-Gaussian TEM11mode are presented.

Comparative numerical study of efficiency of energy deposition in femtosecond microfabrication with fundamental and second harmonics of Yb-doped fiber laser

Paper 7914-111 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Alexandr Dostovalov, Sergey A. Babin, Institute of Automation and Electrometry (Russian Federation); Vladimir K. Mezentsev, Mykhaylo Dubov, Mandana Baregheh, Aston Univ. (United Kingdom)
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We present the results of comparative numerical study of energy deposition in single shot femtosecond laser inscription for fundamental and second harmonic of Yb-doped fiber laser. We have found that second harmonic is more efficient in terms of amount of absorbed energy which leads to lower inscription threshold. Hence this regime is more attractive for applications in femtosecond laser microfabrication.

Defining coiling adiabaticity

Paper 7914-91 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Sylvain O'Reilly, Bertrand Gauvreau, Benoit Sévigny, ITF Labs./Avensys Tech (Canada)
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We present a formalism to quantitatively express the adiabaticity of an optical fiber coil based on normalized coupling coefficient between modes. We present typical coiling configurations on few perspectives: Their geometry, normalized curvature variation path, deviation from the adiabatic curve. Since coiling configurations are of major importance in fiber lasers performances and form factor, a discussion over results and impacts on design rules will follow.

Experimental study of phase locking of fiber collimators using internal beam-tail interference

Paper 7914-108 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Leonid A. Beresnev, U.S. Army Research Lab. (United States); Mikhail A. Vorontsov, Thomas Weyrauch, Univ. of Dayton (United States); Gary W. Carhart, Jiang Liu, U.S. Army Research Lab. (United States)
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Experimental study of near-field phase locking of seven coherent fiber collimators array is described. As a metric of "internal" feedback loop the periphery areas (tails) of beams outgoing from three adjacent fiber tips are used before the beams are clipped by the lens apertures. The intercepted tails of beams were redirected back to collimator array forming the interference pattern in between adjacent collimators. One spot of the pattern was selected by pinhole with photodiode and used as a signal for SPGD controller to lock the phase of three adjacent collimators. For phase locking of seven beamlets three pinholes were used. Signals from three photodiodes placed behind of pinholes allowed us to lock the phase of all seven collimators without bulky beam splitters outside of collimator array.

High-average power optical demodulation of a fiber amplified phase modulated single-frequency signal

Paper 7914-109 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Stephan Rhein, Friedrich-Schiller-Univ. Jena (Germany); Oliver Schmidt, Fraunhofer-Institut für Angewandte Optik und Feinmechanik (Germany); Hagen Zimer, JT Optical Engine GmbH + Co. KG (Germany); Thomas Schreiber, Ramona Eberhardt, Andreas Tünnermann, Fraunhofer-Institut für Angewandte Optik und Feinmechanik (Germany)
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We report to the best of our knowledge on the first proof-of-principle experiment demonstrating high average power (10 W) optical demodulation of a fiber amplified phase-modulated single frequency diode laser signal with a sideband suppression of more than 30 dB. The RF signal for demodulation has been electronically clock synchronized to the modulation frequency with an additional phase shift of pi. This enables us to remove the modulation in a free space lithium-niobate phase modulator to recover a single-frequency signal with sideband suppression of more than 30 dB and additionally, no thermal lensing in the lithium-niobate crystal has been observed.

Impact of modal interference on high-power fiber laser systems

Paper 7914-89 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Cesar Jauregui-Misas, Tino Eidam, Jens Limpert, Friedrich-Schiller-Univ. Jena (Germany); Andreas Tünnermann, Fraunhofer-Institut für Angewandte Optik und Feinmechanik (United States)
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In the last year there have been reports from various research groups around the globe about the onset of modal instabilities in high average power laser systems. This effect is commonly attributed to transversal hole burning, but up to date no theoretical work has been published in the subject to investigate its true physical origin. In this work we present such study and reveal that the interplay of transversal-hole burning and modal interference along the fiber plays a key role in providing high gain for the higher order modes.

In-depth fiber optic two-photon polymerization and its applications in micromanipulation

Paper 7927-44 of Conference 7927
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Yogeshwar N. Mishra, Ninad D. Ingle, Samarendra K. Mohanty, The Univ. of Texas at Arlington (United States)
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Two photon polymerization (TPP) has enabled three-dimensional microfabrication with sub-diffraction limited spatial resolution. However, the depth at which TPP could be achieved has been limited due to the high numerical aperture microscope objective, used to focus the ultrafast laser beam. With the use of an axicon tip (fabricated by chemical etching method), in-depth FTP structures were formed on flat as well as curved surfaces. We will present microfabrication using fiber-optic TPP and micromanipulation of microscopic objects using such microfabricated structures.

Influence of non-linear index on coherent passive beam combining of fiber lasers

Paper 7914-79 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Anatoly P. Napartovich, Troitsk Institute for Innovation and Fusion Research (Russian Federation) and Moscow Institute for Physics and Technology (Russian Federation); Nikolay N. Elkin, Dmitry V. Vysotsky, Troitsk Institute for Innovation and Fusion Research (Russian Federation)
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Coherent laser beam combining is avenue to achieving extremely high brightness of the output beam. Large optical path difference between fiber amplifiers is main obstacle on this way. Cold-cavity theory predicts about 8 lasers at most can be phased. Experiments demonstrated that high degree of phasing takes place for laser array of up to 20 lasers. Explanations of this contradiction rely on laser wavelength self-adjustment and non-linearity of gain and index. Authors showed previously that gain saturation is not sufficient to resolve contradiction. Present studies confirm the hypothesis about strong positive role of index non-linearity in achieving phasing effect.

LMA fibers modal decomposition using image factor analysis

Paper 7914-94 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Jean-Joseph Max, Bertrand Gauvreau, Benoit Sévigny, Mathieu Faucher, ITF Labs./Avensys Tech (Canada)
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We propose a novel application of the factor analysis method commonly used in the field of spectroscopy. The aim is to quantitatively decompose light flux carried by a large mode area fiber on the individual contributions of its supported modes. Access to such cost effective and easy to implement diagnosis tool could largely help improving modal quality preservation in components and systems based on such fibers. The high precision and performance of the method is evaluated using both computer generated and experimental data sets.

Measurement of local polarization for multi-mode photonic crystal fibers

Paper 7914-85 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Oliver A. Schmidt, Christian Schulze, Daniel Flamm, Michael R. Duparré, Friedrich-Schiller-Univ. Jena (Germany)
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Photonic crystal fibers allow the guidance of an elaborately chosen number of modes combined with large mode areas that are essential for high power fiber lasers. The occurring multi-mode beams have spatially inhomogeneous polarization (e.g. radially polarized light) that is significant for several fiber laser applications. We report on a measurement technique to determine this local property using a modal polarization analysis based on a rapid Stokes parameter measurement combined with a computer-generated hologram. We use this method to obtain and visualize the modal polarization states depending on the input polarization as well as the spatially varying polarization ellipses.

Measurement techniques for the evaluation of photodarkening in fibers for high-power lasers

Paper 7914-103 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Guido Perrone, Andrea Braglia, Massimo Olivero, Alessandra Neri, Nadia Boetti, Joris Lousteau, Daniel Milanese, Politecnico di Torino (Italy)
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The photodarkening is one of the impairing characteristics that most affect the widespread use of high power fiber lasers in industrial applications. This phenomenon is evidenced by a degradation of the active fiber performances after long-term exposures to high power densities and is strongly dependent on the fiber composition and manufacturing process. This paper considers different measurements that can be carried out on active "fresh" fibers and critically analyze their capabilities of predicting the effect of photodarkening once the fiber is used in a laser setup. Examples of applications to some commercial fibers are provided.

On the theory of the modulation instability in optical fiber amplifiers and lasers

Paper 7914-113 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Alexander M. Rubenchik, Lawrence Livermore National Lab. (United States); Sergei K. Turitsyn, Aston Univ. (United Kingdom); Michail Fedoruk, Institute of Computational Technologies (Russian Federation)
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Abstract: The modulation instability (MI) in optical fiber amplifiers and lasers with anomalous dispersion leads to CW radiation break-up and growth of multiple pulses. This can be both a detrimental effect limiting the performance of amplifiers, and also an underlying physical mechanism in the operation of MI-based devices. Here we revisit the analytical theory of MI in fiber optical amplifiers. The results of the exact theory are compared with the previously used adiabatic approximation model and the range of applicability of the later is determined. MI dependence on initial conditions is discussed.

Refractive index changes due to gain/absorption in Yb-doped fibers

Paper 7914-50 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Damian N. Schimpf, Enrico Seise, Cesar Jauregui-Misas, Dirk Nodop, Jens Limpert, Andreas Tünnermann, Friedrich-Schiller-Univ. Jena (Germany)
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It is experimentally demonstrated that gain/absorption in Yb-doped fiber amplifiers changes the refractive index. The corresponding phase-shifts are measured using crossed-beam spectral interferometry. We report for the first time to the best of our knowledge, on highly precise measurement of this phase (error < 0.05 rad) over a broad spectral window (~ 30 nm) at ultra fine spectral resolution (~0.05 nm). This measurement allows determining the relative phase-shift contribution due to UV and IR spectral features. The result is of paramount importance for the design of next generation of high power fiber amplifiers. Practical aspects are highlighted.

Second harmonic generation with continuous-wave fiber lasers in periodically-poled non linear crystals

Paper 7914-83 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Mathieu Jacquemet, David Harnois, Alain Mugnier, David Pureur, Quantel Group (France)
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We present in this paper second-harmonic generation (SHG) results of narrow-linewidth continuous-wave 1064 nm fiber lasers in periodically-poled crystals. We particularly compare SHG efficiencies that can be obtained in PPLN with single-frequency linearly-polarized fiber lasers and with narrow linewidth longitudinally multimode linearly-polarized fiber lasers. Both infrared lasers can provide around 4.5W at 1064nm. Due to the high number of modes, sum-frequencies between modes enhance the efficiency of multimode SHG by a factor of roughly 2 compared to single-frequency, but green generated radiation suffers from important intensity noise. Conversely, single-frequency SHG is less efficient, but intensity noise is greatly improved.

The high-power femtosecond pulses amplified by an all-fiber system based on the model of self-similar amplification

Paper 7914-101 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Tianxin Yang, Tianhe Wang, Delin Yang, Junlong Wang, Mei Sang, Tianjin Univ. (China)
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In this paper a theoretical model of self-similar amplifications is studied experimentally in an all-fiber high power amplifier. The output vs. input characteristics of this amplifier are measured when the various femtosecond pulses at different energies and different shapes are inputted. It is verified that the all-fiber high power amplifier system is indeed operating in the way of self-similar amplifications by analyzing the data of the amplified pulses along with the data of the input pulses. Finally, nearly transform-limited ultra-short pulses with high average power of 500 mW and time-bandwidth product of 0.342 are obtained by compressing the output pulses from the fiber amplifier to the ultra-short pulses of 113 fs at the center wavelength of 1552 nm using a segment of DCFs with large negative group velocity dispersion. The results demonstrated that the operating mode of the amplifier is consistent with the typical self-similar amplification model.

Low loss and broadband hollow-core photonic crystal fibers

Paper 7946-32 of Conference 7946
Date: Wednesday, 26 January 2011
Time: 8:20 AM – 8:50 AM

Author(s): Fetah A. Benabid, Yingying Wang, Univ. of Bath (United Kingdom)
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We report on the late developments on hollow-core photonic crystal fibers that ensure both low optical transmission loss and ultra-broad optical bandwidth.

Novel concept for long-haul ultrashort pulse fiber delivery without pre-chirping

Paper 7912-41 of Conference 7912
Date: Wednesday, 26 January 2011
Time: 8:20 AM – 8:40 AM

Author(s): Tuan Le, Gabriel Tempea, Andreas Stingl, FEMTOLASERS Produktions GmbH (Austria); Kim G. Jespersen, OFS Fitel Denmark ApS (Denmark); Karin Wiesauer, RECENDT GmbH (Austria)
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Ultrashort pulse fiber delivery for Ti:Sapphire lasers is basically restricted to distances below several meters which is due to the application of dispersion compensating devices that are not capable managing third and higher order material dispersion. By the use of a novel fiber delivery concept ultrashort laser pulses in the 800 nm wavelength range can now be transmitted over tens of meters without the need for any pulse pre-compression. For the first time a long-haul fiber delivery module will be demonstrated revealing its potential for remote imaging or THz spectroscopy with femtosecond laser pulses.

Beam steering mirror for fine adjustment of visible laser single mode fiber coupling based on a birefringent crystal

Paper 7912-42 of Conference 7912
Date: Wednesday, 26 January 2011
Time: 8:40 AM – 9:00 AM

Author(s): Christian Kannengiesser, Ruediger von Elm, Wolf Seelert, Coherent Lubeck GmbH (Germany)
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High precision beam steering usually requires complex and sophisticated mechanics to keep the alignment tolerances stable over the long term. In this talk, we will present a simple temperature- controlled steering device that is based on a crystal with different temperature expansion coefficients along its axes. Results for single mode fiber coupling of visible lasers will be presented.

Pulsed Tm3+-doped fiber amplifier with 300-W average output power

Paper 7914-41 of Conference 7914
Date: Wednesday, 26 January 2011
Time: 9:00 AM – 9:20 AM

Author(s): Yulong Tang, Lin Xu, Yi Yang, Shanghai Institute of Optics and Fine Mechanics (China); Jianqiu Xu, Shanghai Jiaotong Univ. (China)
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Combining a high-power Q-switched Tm:LuLiF crystal laser and two-stage large-fiber-core Tm3+ fiber amplifiers, 300-W average-power 2-µm pulsed laser output has been realized, with a slope efficiency of ~50% with respect to 790-nm launched pump. The high-power output originated from efficient suppression of ASE, 10-degree angle cleavage of fiber ends, and retro-feedback block of signal beam with optical isolators. At all amplification levels, no evident SBS (stimulated Brillouin scattering) or SRS (stimulated Raman scattering) signal was observed. Amplified pulse duration can be tuned between tens of ns and ~1 µs, and the pulse repetition rate can be changed from 500 Hz to 50 kHz. The maximum pulse energy was over 20 mJ, and the maximum pulse peak power was over 200 kW. By using the fiber-coiling-induced mode-filtering effect, output beam quality of M2<1.2 was obtained.

High-power pulse-pumped solid state laser gain modules

Paper 7912-45 of Conference 7912
Date: Wednesday, 26 January 2011
Time: 9:40 AM – 10:00 AM

Author(s): Jay Doster, Ryan Feeler, Northrop Grumman Cutting Edge Optronics (United States)
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Northrop Grumman Cutting Edge Optronics (NGCEO) has developed a line of pulse-pumped solid-state laser gain modules for industrial and scientific applications. These modules produce output energies up to 4 J/pulse when used as oscillators. When used as amplifiers, these modules produce small signal gains in excess of 600. Various case studies are presented and include: high-energy pulse generation, repetitive pulse amplification, and pulse-train amplification. Particular emphasis is paid to maintaining beam quality, minimizing depolarization, and maximizing pump uniformity. A comparison between fiber lasers and lasers built from these modules is presented in order to further define the application space.

Fiber-optic Cherenkov radiation excited by few-cycle pulses

Paper 7937-57 of Conference 7937
Date: Wednesday, 26 January 2011
Time: 9:55 AM – 10:20 AM

Author(s): Guoqing Chang, Li-Jin Chen, Franz Kaertner, Massachusetts Institute of Technology (United States)
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Fiber-optic Cherenkov radiation (CR) has emerged as a wavelength conversion technique to achieve isolated spectrum in the visible wavelength range. Most published results have reinforced the impression that CR forms narrowband spectrum with poor efficiency. We have both numerically and experimentally investigated CR in the few-cycle pulse regime. Our results demonstrated that CR, when pumped with 10 fs pulses of more than 200 pJ pulse energy, exhibits high conversion efficiency (>40%), broad bandwidth (>50 nm), and low threshold (<100 pJ for pulse energy). These three merits allow achieving broadband visible-wavelength spectra from low-energy ultrafast sources which opens up new applications.

Diffractive and subwavelength waveguide structures and their applications in nanophotonics, sensing, and spectroscopy

Paper 7941-39 of Conference 7941
Date: Wednesday, 26 January 2011
Time: 10:40 AM – 11:10 AM

Author(s): Pavel Cheben, Przemek Bock, Jens Schmid, Jean Lapointe, Siegfried Janz, Danxia Xu, Rubin Ma, Adam Densmore, Boris Lamontagne, National Research Council Canada (Canada); Trevor Hall, Univ. of Ottawa (Canada); Robert Halir, Carlos Ramos, Alejandro Monux, Inigo Molina-Fernandez, Juan Wanguemert-Perez, Univ. de Málaga (Spain)
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We present a new type of microphotonic waveguide, exploiting the subwavelength grating (SWG) effect. The SWG technique allows for engineering refractive index of a waveguide core over a range as broad as 1.5-3.5 simply by lithographic patterning using only two materials, e.g. Si and SiO2. A SWG fibre-chip coupler for Si-wire waveguides is presented with a loss as small as 0.9 dB and with minimal wavelength dependence over a broad wavelength range exceeding 200 nm. It is also shown that the SWG waveguides can be used to make efficient waveguide crossings with minimal loss and negligible crosstalk. We also present a diffractive surface grating coupler with subwavelength nanostructures designed for silicon-wire biological sensors. Finally, the first surface grating couplers for a silicon ridge waveguide of micrometer dimensions are reported.

A flexible rugged testbed for passive solar collector development

Paper 7954-19 of Conference 7954
Date: Wednesday, 26 January 2011
Time: 11:20 AM – 11:40 AM

Author(s): Balaji Srinivasan, A. N. Bharathwaj, Anand Mishra, Indian Institute of Technology Madras (India)
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We report the development of a flexible, rugged testbed for the purpose of testing various passive solar light collector configurations. An essential aspect in evaluating the performance of such collectors is to analyze its behavior under various illumination levels and planes of incident light. The test bed consists of a series of white LED assemblies which are digitally controlled using a micro-controller and is mounted on an rugged frame. The intensity levels of the LED can be controlled through a computer to emulate the sun's radiation effectively. The module also consists of a detector plane which houses four photodetectors for data collection.

Hybrid optical transport trap: loading and unloading of microscale objects using a microfabricated optical fiber into optical tweezers

Paper 7950-7 of Conference 7950
Date: Wednesday, 26 January 2011
Time: 11:40 AM – 12:00 PM

Author(s): Yogeshwar N. Mishra, Cochin Univ. of Science & Technology (India); Nelson Cardenas, Samarendra K. Mohanty, The Univ. of Texas at Arlington (United States)
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We demonstrate development of a hybrid optical transport trap (HOTT) which combines a tapered fiber-optic trap for transport of microscopic objects into and out of the optical tweezers trap in an orthogonal geometry. The tapered fiber tip was fabricated by chemical etching method.For small cone angle of the tip, the microscopic objects (polystyrene and red blood cells) were found to be trapped in 2-D and pushed along the axial direction by domination of scattering force. While for loading of the microscopic objects into the optical tweezers trap, the fiber tip was placed ~ 30 microns away from the tweezers trap, unloading was carried out in presence of the tip close (<15 microns) to the tweezers trap. Further, for a fixed fiber trap and tweezers separation (~ 30 microns), both loading and unloading could be achieved by reducing the tweezers trap power so that the scattering force exerted by the fiber trap exceeded the transverse gradient force of tweezers trap.

Inexpensive 3dB coupler for POF communication by injection-molding production

Paper 7959-8 of Conference 7959
Date: Wednesday, 26 January 2011
Time: 12:00 PM – 12:20 PM

Author(s): Matthias Haupt, Ulrich H. P. Fischer, Hochschule Harz (Germany)
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POFs (polymer optical fibers) gradually replace traditional communication media. POFs are used in various fields of optical communication, e.g. the automotive sector or in-house communication. So far, however, only a few key components for a POF communication network are available. Even basic components, such as splices and couplers, are fabricated manually. Therefore, these circumstances result in high costs and fluctuations in components' performance. Available couplers are hand made and, hence, expensive. In order to produce couplers with higher performances new fabrication methods are indispensable. The paper gives an overview of couplers available on market, compares their performance, and shows a way to produce 3dB couplers by means of injection molding.



Highly nonlinear tellurite microstructured fibers for broadband wavelength conversion and flattened supercontinuum generation

Paper 7934-23 of Conference 7934
Date: Wednesday, 26 January 2011
Time: 1:30 PM – 1:50 PM

Author(s): Guanshi Qin, Xin Yan, Chihiro Kito, Meisong Liao, Takenobu Suzuki, Yasutake Ohishi, Toyota Technological Institute (Japan)
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We demonstrate four-wave mixing based broadband (>68 nm) wavelength conversion and flattened supercontinuum generation spanning from 900 to 2800 nm in a 36-cm long tellurite microstructured fiber which has a high nonlinearity. By reducing the size of air holes of the tellurite microstructured fibers, single mode propagation and small dispersion slope are obtained without the propagation loss enhancement. Our results show that chromatic-dispersion controlled tellurite microstructured fibers are promising candidates for nonlinear applications.

Scaling technologies for terabit fiber optic transmission systems

Paper 7942-5 of Conference 7942
Date: Wednesday, 26 January 2011
Time: 1:30 PM – 2:00 PM

Author(s): David V. Plant, McGill Univ. (Canada)
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The past decade has seen profound changes not only in the way we communicate, but also in our expectations of what networks will deliver in terms of speed and. The coming decade promises to demand more capacity and bandwidth in these networks and it is in this context that we will present work on scaling technologies for terabit fiber optic transmission systems. We will discuss several topics that focus on increasing capacity in existing and next generation long-haul and metro fiber optic transmission systems that will carry tens to hundreds of terabits and will be based on coherent optical receivers.

Structured material combined HMO-silica fibers: preparation, optical and mechanical behaviour

Paper 7934-24 of Conference 7934
Date: Wednesday, 26 January 2011
Time: 1:50 PM – 2:10 PM

Author(s): Kay Schuster, Jens Kobelke, Doris Litzkendorf, Anka Schwuchow, Florian Lindner, Johannes Kirchhof, Hartmut Bartelt, Institut für Photonische Technologien e.V. (Germany); Jean-Louis Auguste, Georges J. Humbert, Univ. de Limoges (France)
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Transmission characteristics of a modal interferometer based on a polarization-maintaining photonic crystal fiber depending on input polarization states

Paper 7934-26 of Conference 7934
Date: Wednesday, 26 January 2011
Time: 2:30 PM – 2:50 PM

Author(s): Young-Geun Han, Hyun-Joo Kim, Hanyang Univ. (Korea, Republic of)
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In this letter, a modal interferometer based on a polarization-maintaining photonic crystal fiber depending on two orthogonal input polarization states is investigated. The different wavelength spacing of the modal interferometer is observed by changing input polarization states. The proposed interferometer differently responds to temperature and ambient index change as the input polarization states are changed.

Dielectric optical waveguides using periodic layers of metamaterials and dielectrics

Paper 7945-83 of Conference 7945
Date: Wednesday, 26 January 2011
Time: 3:05 PM – 3:20 PM

Author(s): Anjan K. Ghosh, Pramode Verma, The Univ. of Oklahoma - Tulsa (United States)
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A stack of alternating layers of dielectrics with positive refractive index and metamaterials with negative refractive index can be tuned to a vanishing average refractive index. The design and performance of a stripped cladding fiber optic evanescent field sensor built with a stack are investigated in this paper.

A novel fabrication technique of long-period fiber gratings based on periodic ridge structures in the cladding of a single-mode fiber

Paper 7934-28 of Conference 7934
Date: Wednesday, 26 January 2011
Time: 3:40 PM – 4:00 PM

Author(s): Young-Geun Han, Oh-Jang Kwon, Sang-Oh Park, Hanyang Univ. (Korea, Republic of)
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In this paper, a novel fabrication method of long-period fiber gratings (CLPFG) based on periodic ridge structures in the cladding of a single-mode fiber is proposed and experimentally demonstrated for mass production. The proposed fabrication technique of LPFGs is based on double layers of polymer coatings surrounding a single-mode fiber.A high quality of the transmission with a high extinction ratio of 15 dB was obtained. The peak depth was controlled by changing the applied tensile strain without center wavelength shift.

Analogue modulation performance of 20 GHz vertical cavity surface emitting lasers for radio over fiber applications

Paper 7933-48 of Conference 7933
Date: Wednesday, 26 January 2011
Time: 3:50 PM – 4:20 PM

Author(s): Richard V. Penty, Ian H. White, Zihad Qureshi, Jonathan D. Ingham, Michael J. Crisp, Univ. of Cambridge (United Kingdom); Nikolay N. Ledentsov, James A. Lott, VI Systems GmbH (Germany)
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850 nm VCSELs are the dominant light sources for short reach optical networks operating at bit rates to 10 Gbps and beyond. Alongside recent improvements in digital transmission data rates, there is also current research interest in devices with high bandwidth and linearity which will be required to support advanced modulation formats and for next generation Radio-over-Fibre (RoF) applications. This paper will describe the use of oxide confined GaAs/InGaAs VCSELs designed for high-speed modulation at low current densities for these applications.

Convergence of broadcasting and communications utilizing CATV network

Paper 7958-11 of Conference 7958
Date: Wednesday, 26 January 2011
Time: 4:00 PM – 4:30 PM

Author(s): Kazuo Kumamoto, Hikaru Hoshino, Koji Yasukawa, Osaka Institute of Technology (Japan); Takeshi Higashino, Katsutoshi Tsukamoto, Shozo Komaki, Osaka Univ. (Japan); Keizo Inagaki, National Institute of Information and Communications Technology (Japan)
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A so-called digital divide problem which is difference caused in information and communication service offered between regions is becoming social problems in Japan. Authors are investigating about a new solution of digital divide problem utilizing Radio over Fiber technology. This paper will show overview of the project and propose a cost-effective system configuration. Moreover, some results of field trials will be demonstrated.

High-power diode-pumped Q-switched Er3+:YAG single-crystal fiber laser

Paper 7912-53 of Conference 7912
Date: Wednesday, 26 January 2011
Time: 4:20 PM – 4:40 PM

Author(s): Igor Martial, Lab. Charles Fabry (France) and FiberCryst (France); Julien Didierjean, Nicolas Aubry, FiberCryst (France); François Balembois, Patrick Georges, Lab. Charles Fabry (France)
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Er3+:YAG is an attractive material for the development of compact eye safe laser sources around 1.6 µm. Because of temperature dependence of spectroscopic parameters and up-conversion effects, low doped samples are required to achieve efficient lasers. Single-crystal fibers can address these requirements while managing the poor beam quality of pump laser diodes through the guiding of the pump beam. In this work an Er3+:YAG single-crystal fiber is pumped by a high power laser diode at 1532 nm. We obtained an output power of 12.5 W in CW and 40 ns, 2 mJ pulses at 1 kHz in Q-switched operation.

Performance analysis of IM/DD radio-on-fiber link for transmitting multicarrier RF signals

Paper 7958-12 of Conference 7958
Date: Wednesday, 26 January 2011
Time: 4:30 PM – 4:50 PM

Author(s): Takeshi Higashino, Satoru Okumura, Katsutoshi Tsukamoto, Shozo Komaki, Osaka Univ. (Japan); Kazuo Kumamoto, Koji Yasukawa, Osaka Institute of Technology (Japan); Keizo Inagaki, National Institute of Information and Communications Technology (Japan)
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Nowadays, the RoF technology can utilize to converge the broadcasting and the broadband wireless communications, because of their huge bandwidth, and protocol transparency. Transmitting RF signals are deteriorated by the nonlinearity of the RoF link and following RF amplifier. This paper provides analysis method of intermodulation distortion and peak factor of multicarrier RF signals including IEEE802.11g, ISDB-T and IEEE802.16e-2005 over intensity modulation / direct detection (IM/DD) RoF link. Experimental evaluation is also presented in terms of the error vector magnitude (EVM) and peak to average power ratio (PAPR).

Scaling 100G QPSK links for reliable network development

Paper 7959-11 of Conference 7959
Date: Wednesday, 26 January 2011
Time: 4:30 PM – 4:50 PM

Author(s): Andrew J. Stark, Steven Searcy, Yu-Ting Hsueh, Tom Detwiler, Georgia Institute of Technology (United States); Sorin Tibuleac, Mark Filer, ADVA Optical Networking North America, Inc. (United States); Gee-Kung Chang, Stephen Ralph, Georgia Institute of Technology (United States)
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Using both simulation and experimental results from our 100G testbed we investigate the use of a nonlinear phase criterion that quantifies the total nonlinear phase accumulation within a 112 Gb/s PDM-QPSK link. In order to assess the applicability of a nonlinear phase criterion on real-world links, we determine the launch power that yields a 1.5 dB OSNR penalty at a BER of 10^-3 for each configuration. This launch power then allows the identification of a Nonlinear Threshold Power (number of spans times launch power) that fully incorporates the increasing nonlinear penalties with further transmission distance.

Mid-IR lasing of Cr:ZnSe/As2S3:As2Se3 composite materials

Paper 7912-55 of Conference 7912
Date: Wednesday, 26 January 2011
Time: 5:00 PM – 5:20 PM

Author(s): Dmitri V. Martyshkin, Vladimir V. Fedorov, The Univ. of Alabama at Birmingham (United States) and IPG Photonics Corp. (United States); Jonathan T. Goldstein, Air Force Research Lab. (United States); Sergey B. Mirov, The Univ. of Alabama at Birmingham (United States) and IPG Photonics - Mid-Infrared Lasers (United States)
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The proposed transition metal doped Cr:ZnSe/As2S3:As2Se3 composite materials with index matching of II-VI and V-VI components represent a new way for design of mid-infrared laser active fibers. It allows combining chalcogenide glasses as a host mid-IR fiber material with chromium doped II-VI semiconductor compounds which proved to be excellent mid-IR gain material. Chalcogenide glasses capability to vary refractive index from n=2.1 to n=2.5 provides a pathway to refractive index optimization and matching to ZnS (n=2.26) and ZnSe (n=2.44) crystals eliminating scattering losses. We report the first to our knowledge room-temperature laser oscillation of Cr: ZnSe/As2S3:As2Se3 compound at 2.4 µm.

spectrally efficient polymer optical fiber transmission

Paper 7960-23 of Conference 7960
Date: Wednesday, 26 January 2011
Time: 5:00 PM – 5:30 PM

Author(s): Sebastian Randel, Alcatel-Lucent Bell Labs. (United States); Christian-Alexander Bunge, Hochschule für Telekommunikation Leipzig (Germany)
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The polymer optical fiber (POF) made of polymethyl methacrylate (PMMA) is an attractive transmission medium for high speed communication links in home networks, in automotive infotainment networks, and in industrial automation. Growing demands for quality of service, e.g., for IPTV distribution in homes and for Ethernet based industrial control networks will necessitate gigabit speeds in near future. The authors will present an overview on recent advances in the design of spectrally efficient and robust gigabit over POF transmission systems.

2×2 Photonic crystal fiber splitter for 800 nm spectral domain optical coherence tomography

Paper 7933-82 of Conference 7933
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Joo Beom Eom, Gwangju Institute of Science and Technology (Korea, Republic of) and Korea Photonics Technology Institute (Korea, Republic of); Eun Jung Min, Kwan Seob Park, Seong Jun Park, Gwangju Institute of Science and Technology (Korea, Republic of); Hae-Ryong Lim, Jong-Hyuk Park, Korea Photonics Technology Institute (Korea, Republic of); Byeong-Ha Lee, Gwangju Institute of Science and Technology (Korea, Republic of)
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We report on the fabrication and performance of 2×2 Photonic crystal fiber (PCF) splitter which was designed as single mode splitter at 800 nm optical band. PCF splitter has been made by PCF-to-PLC connections. PCF array blocks were lithographically fabricated to have fiber V grooves and used to firmly hold PCFs. PLC chip was also fabricated to have single mode property at 800 nm wavelength. The core size of splitter chip was about 5 um × 5 um and the core-cladding index difference was about 0.15%. With the implemented PCF PLC splitter, we obtained a low excess loss of 1.2 dB at 850 nm, a low polarization-dependent loss of 0.19 dB. With the proposed 2×2 Photonic crystal fiber (PCF) splitter, OCT images of an in vitro biological sample were successfully obtained.

Design of closed-loop double-cell self-phase modulation based optical regenerator

Paper 7934-57 of Conference 7934
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Karin M. Ennser, Stefano Taccheo, Swansea Univ. (United Kingdom); Giorgio Tosi Beleffi, Istituto Superiore delle Comunicazioni e delle Tecnologie dell'Informazione (Spain)
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In this paper, a closed-loop, two-cell, self-phase modulation based optical regenerator is proposed and optimised to reduce signal noise and distortion. The results have shown that a significant Q-factor improvement and jitter suppression are achieved after travelling the optical regenerator a few times; however it is sensitive to power variations. Relevant design rules are discussed and the robustness assessed.

Energy enhancement in mode-locked lasers using sinusoidal transmission functions for saturable absorption

Paper 7933-73 of Conference 7933
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Edwin Ding, Eli Shlizerman, Jose Nathan Kutz, Univ. of Washington (United States)
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The mode-locking dynamics in a ring cavity laser mode-locked with a combination of waveplates and a passive polarizer are typically modeled by the master mode-locking equation. However, this equation fails to account for the sinusoidal transmission function provided by the discrete mode-locking elements in the cavity. We generalize the master equation to more accurately model the experimentally verified transmission function. Explicitly accounting for the sinusoidal transmission function suggests methods for orienting the waveplates that can greatly enhance the laser performance and energy output. We optimize the laser cavity performance and suggest the specific ways that this can be done experimentally.

Fabrication of long-period fiber grating based on a periodic micro-tapering technique

Paper 7934-35 of Conference 7934
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Young-Geun Han, Min-Seok Yoon, Hanyang Univ. (Korea, Republic of)
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In this paper, a novel fabrication technique of the LPFG based on a micro tapering method is presented. The micro tapering method is composed of two simultaneous processes. One is a heating process and the other is an elongation process by using a pulling device. Control the elongation speed of pulling device and the temperature of heating process can change the structure of fiber without unwanted defect. The micro tapering method does not need high cost equipment, such as CO2 laser, hydrogen loaded fiber and amplitude mask. Process of micro tapering method is simple. And parameters of LPFG are easily adjustable. Therefore, the micro tapering method is very useful for fabrication of fiber gratings.

GAWBS and its effect on SBS based slow light in optical fibers

Paper 7937-69 of Conference 7937
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Christopher K. Horne, Chung Yu, Khanh Tranh, North Carolina A&T State Univ. (United States)
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Stimulated Brillouin scattering (sBs) and slow light in fibers and nano-structures have been studied in detail. We observe the optical fiber ring to increase slow light by lowering the sBs threshold, increasing gain and reducing linewidth, but also multiple sBs lines originating by guided acoustic wave Brillouin scattering (GAWBS). Multiple sBs lines and slow light have not been noted in the literature. We report our findings of GAWBS modes slow light in optical fibers. If GAWBS modes are observed in the forward direction, then what is the effect on the sBs backward Stokes wave in a slow light device?

Measurement of a single polarization state and transmission characteristics of a Sagnac loop interferometer based on a single polarization fiber

Paper 7934-34 of Conference 7934
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Young-Geun Han, Oh-Jang Kwon, Hanyang Univ. (Korea, Republic of)
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In this paper, we investigate the interference characteristics of a SPF-based Sagnac loop mirror. Since the SPF has two cutoff wavelengths (cutoff-1 and cutoff-2) corresponding to two orthogonal input polarization states, a single polarization mode is only propagated in a specific wavelength range, which induces peculiar interference patterns. We also measure the transmission characteristics of the SPF-based Sagnac interferometer as the applied temperature and strain are changed

Novel method for fabrication of metal- or oxide-nanoparticle doped silica-based specialty optical fibers

Paper 7934-33 of Conference 7934
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Borut Lenardic, Miha Kveder, Optacore d.o.o. (Slovenia); Darja Lisjak, Jožef Stefan Institute (Slovenia); Herve Guillon, Samuel Bonnafous, KEMSTREAM (France)
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Nanoparticle-doped optical fibers are causing significant scientific interest in different fields of application. For their fabrication novel "flash vaporization" method is proposed. This technology is based on impulse evaporation of finely distributed aerosols, generated from suspensions containing nanoparticles and organic solvent. Doping of silica layers by nanoparticles was achieved on standard MCVD system, equipped by "flash vaporization" doping device. Copper and Er/Al - oxide nanoparticles were used in these experiments. Presence of nanoparticles was confirmed in deposited layers. Optimized "flash vaporization" method can provide several advantages over other nanoparticle deposition technologies and is suitable for use in MCVD and OVD process.

Performance of randomly distributed holes optical fibers under low dose gamma-ray irradiation

Paper 7934-58 of Conference 7934
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Bassam Alfeeli, Shree Narayanan, Doug Smiley, Donald Conner, Jr., Gary Pickrell, Virginia Polytechnic Institute and State Univ. (United States)
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We present the effects of low-dose gamma-ray irradiation on a newly developed randomly distributed holes optical fiber (RDHF). The fiber has a cladding diameter of 125µm and 0.21dB/km attenuation in the 1550nm wavelength. The effect of gamma irradiation on the presented fibers was studied by comparing their transmission performance with standard single-mode telecommunication fiber (SMF). RDHF along with SMF were irradiated with 0.662MeV gamma-rays at absorbed dose of 4mGy(Si)/hr and total dose of 1.5Gy(Si). Results revealed that the performance of fibers under irradiation is not only dependent on the bulk material but also on the physical structure of the fiber.

Soliton self-frequency shift in tellurite microstructured fiber

Paper 7934-38 of Conference 7934
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Xin Yan, Guanshi Qin, Meisong Liao, Takenobu Suzuki, Yasutake Ohishi, Toyota Technological Institute (Japan)
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In this paper, we report broad near-infrared soliton source generation in a TeO2-Bi2O3-ZnO-Na2O (TBZN) tellurite microstructured optical fiber (MOF) pumped by a 1557 nm femtosecond fiber laser. A continuous soliton wavelength shift from 1582 nm to 1851 nm was realized through a tellurite MOF as short as 6.5 cm. Experimental results are in good agreement with the numerical simulations using a generalized nonlinear SchrÖdinger equation. In addition, an analytical description of the Raman response function of tellurite glass is provided, and a Raman contribution factor of 0.51 is computed from the actual Raman gain spectrum.

Recent advances in the front-end sources of the LMJ fusion laser

Paper 7916-17 of Conference 7916
Date: Thursday, 27 January 2011
Time: 8:30 AM – 8:50 AM

Author(s): Jean-François Gleyze, Nicolas Beck, Jerome Dubertrand, Arnaud Perrin, Commissariat à l'Énergie Atomique (France)
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In lasers for inertial confinement fusion, like LMJ, main amplifier is injected by a laser source in which the beam parameters must be controlled. For several years the CEA has developed front end fibre sources, based on the telecommunications fibre optics technologies. These sources meet the needs but as technology evolves, the solutions used could be more efficient at a lower cost and with a smaller footprint. We give an up-to-date description of some present development issues, particularly in the field of temporal shaping with the use of digital system, but also in the robustness of the spectral broadening system.

Fiber-MOPA based, multi-aperture, multi-kW, uplink laser beacon for deep-space laser communication links

Paper 7923-12 of Conference 7923
Date: Thursday, 27 January 2011
Time: 8:40 AM – 9:00 AM

Author(s): Doruk Engin, Wei Lu, Frank Kimpel, Youming Chen, Mehmetcan Akbulut, Shantanu Gupta, Fibertek, Inc. (United States)
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Multi-aperture, multi-kW average power, uplink laser beacons are needed for deep space lasercomm links, to mitigate effects of atmospheric layer turbulence. An 8-channel Yb-fiber-MOPA based laser beacon architecture is demonstrated at 1064nm. For 100nsec pulsewidth, at 1 MHz repetition rate (10% duty-cycle), representative of 8-ary/16-ary PPM pulse format, power-scaling to >5kW peak powers (>500W avg. power) for a channel is demonstrated, with >70% optical conversion efficiency, near diffraction-limited beam, and OSNR>35dB. Programmable pulse formation, pulse shaping to mitigate effect of gain-saturation, as well as all laser control functions are implemented via high-speed FPGA, leading to a flexible configuration. For operation at <1030nm, conversion efficiency suffers, but can be mitigated using Yb-fiber designs with larger core/clad ratio.

Global sensitivity analyses of coherent beam combining of fiber amplifier arrays by the use of numerical space filling designs

Paper 7914-52 of Conference 7914
Date: Thursday, 27 January 2011
Time: 9:10 AM – 9:30 AM

Author(s): Adrian Azarian, Olivier Vasseur, Baya Bennaï, Laurent Lombard, Guillaume Canat, ONERA (France); Véronique Jolivet, ONERA, (France); Yves Jaouën, Telecom ParisTech (France); Pierre Bourdon, ONERA (France)
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In coherent beam combining, the phase errors at the output of each beam of an array of fiber amplifiers have to be corrected. In order to evaluate the beam combining process stability, we propose a new technique based on numerical space filling designs to perform sensitivity analyses on two different array configurations and two different shaped wavefronts. By the use of a metamodel, we present results assessing the role of each fiber as well as interactions between fibers onto the combination efficiency. We demonstrate that our methodology can be used to study arrays of more than 100 fibers.

The progress of the front-end and preamplifier in PW and SG-II

Paper 7916-19 of Conference 7916
Date: Thursday, 27 January 2011
Time: 9:10 AM – 9:30 AM

Author(s): Xuechun Li, Wei Fan, Shanghai Institute of Optics and Fine Mechanics (China)
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Power scaling and high-power applications of a femtosecond enhancement cavity

Paper 7914-54 of Conference 7914
Date: Thursday, 27 January 2011
Time: 10:00 AM – 10:30 AM

Author(s): Ioachim Pupeza, Max-Planck-Institut für Quantenoptik (Germany) and Ludwig-Maximilians-Univ. München (Germany); Tino Eidam, Friedrich-Schiller-Univ. Jena (Germany); Jan Kaster, Jens Rauschenberger, Max-Planck-Institut für Quantenoptik (Germany) and Ludwig-Maximilians-Univ. München (Germany); Birgitta Bernhardt, Akira Ozawa, Ernst E. Fill, Max-Planck-Institut für Quantenoptik (Germany); Vladimir Pervak, Ludwig-Maximilians-Univ. München (Germany); Alexander A. Apolonski, Max-Planck-Institut für Quantenoptik (Germany) and Ludwig-Maximilians-Univ. München (Germany); Thomas Udem, Max-Planck-Institut für Quantenoptik (Germany); Jens Limpert, Friedrich-Schiller-Univ. Jena (Germany); Zeyad A. Alahmed, Abdallah M. Azzeer, King Saud Univ. (Saudi Arabia); Andreas Tünnermann, Friedrich-Schiller-Univ. Jena (Germany); Theodor W. Hänsch, Ferenc Krausz, Max-Planck-Institut für Quantenoptik (Germany) and Ludwig-Maximilians-Univ. München (Germany)
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We discuss the power scalability of a bow-tie enhancement cavity, seeded by an Yb-based fiber CPA system. The seed laser parameters are: 78 MHz repetition frequency, 200 fs pulse duration and 50 W of maximum average power. Peak intensities exceeding 10^14 W/cm^2 at the 22 µm-radius cavity focus (1/e^2-intensity) for several enhancement regimes with circulating powers of up to 72 kW are demonstrated. We find that the enhancement is primarily limited by intensity-dependent processes occurring in the cavity mirrors, such as third-harmonic generation and nonlinear group delay dispersion and we propose solutions to overcome these limitations. We report on our group's recent progress regarding the applications of this system.

In-vivo third-harmonic generation microscopy at 1550 nm: three-dimensional long-term time-lapse studies in living C. elegans embryos

Paper 7904-50 of Conference 7904
Date: Thursday, 27 January 2011
Time: 11:10 AM – 11:30 AM

Author(s): Rodrigo A. Aviles-Espinosa, Susana I. C. O. Santos, ICFO - Instituto de Ciencias Fotónicas (Spain); Andreas Brodschelm, Wilhelm G. Kaenders, TOPTICA Photonics AG (Germany); Cesar Alonso-Ortega, ICFO - Instituto de Ciencias Fotónicas (Spain); David Artigas-García, ICFO - Instituto de Ciencias Fotónicas (Spain) and Univ. Politècnica de Catalunya (Spain); Pablo Loza-Alvarez, ICFO - Instituto de Ciencias Fotónicas (Spain)
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In-vivo microscopic three-dimensional time-lapse studies (4D) require controlled exposure conditions to preserve sample viability. In this work, we use a 1550nm femtosecond fiber laser to obtain different tissue/structure information of living Caenorhabditis elegans embryos. By exciting Third harmonic generation at 1550nm, the emitted signal is generated at 516nm, enabling the use of standard collection optics and detectors operating near their maximum efficiency. This enables an incident power reduction allowing sample exposure for several hours. Our technique significantly reduces, sample interference (no external markers are required), demonstrating the non-invasiveness and strong potential of this particular wavelength to perform 4D studies.

Radiation balanced holmium fiber lasers

Paper 7951-7 of Conference 7951
Date: Thursday, 27 January 2011
Time: 11:10 AM – 11:40 AM

Author(s): Steven R. Bowman, Nicholas J. Condon, Shawn O'Connor, U.S. Naval Research Lab. (United States); Thomas Ehrenreich, Scott Christensen, Nufern (United States)
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In order to increase the average power of fiber lasers, we are exploring the possibility of operating holmium fibers lasers near the radiation balance condition. At the radiation balance condition, the absorbed optical power is equal to the total radiated optical power; with negligible waste heat. Specifically, we are considering a single-mode 2.1μm Ho:Silica fiber lasers that is resonant pumped using several multi-mode thulium fiber lasers. The analysis of performance and projected power flow in this novel type of fiber laser will be presented.

All-optical demultiplexer based on dynamic multiple holograms for optical MIMO processing and mode division multiplexing

Paper 7958-17 of Conference 7958
Date: Thursday, 27 January 2011
Time: 11:20 AM – 11:40 AM

Author(s): Takuya Oda, Atsushi Okamoto, Daiki Soma, Akihisa Tomita, Yuta Wakayama, Hokkaido Univ. (Japan)
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We propose an all-optical demultiplexer based on dynamic multiple holograms by using a photorefractive material for mode division multiplexing and optical MIMO processing. This demultiplexer can separate a specific spatial mode from multiplexed modes in a multi-mode fiber. In this study, we evaluate a mode separation performance with various combinations of LP modes and find out suitable combinations. The diffraction efficiency and separation ratio is improved by inserting a random phase mask before demultiplexing and by adjustment of some optical parameters. Finally, we examine the method of automatically rewriting the hologram to respond the change of the spatial mode.

Passive mode-locking using multi-mode fiber

Paper 7914-56 of Conference 7914
Date: Thursday, 27 January 2011
Time: 11:20 AM – 11:40 AM

Author(s): Edwin Ding, Jose Nathan Kutz, Univ. of Washington (United States); Simon Lefrancois, Frank W. Wise, Cornell Univ. (United States)
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A multi-mode fiber laser is investigated both experimentally and theoretically in an effort to increase the energy content of the generated mode-locked pulses. At the expense of propagating higher-order modes, the larger core area fibers allow for a reduction in the nonlinear penalties generated by the high peak powers. With judicious engineering, the multi-mode fiber can be shown to outperform standard single-mode fiber lasers. However, the mode-locking performance is highly sensitive to the presence of higher-order mode content. We characterize the optimal performance as a function of higher-order mode suppression and mode-coupling strength.

Generation and amplification of 350 fs, 2 μm pulses in Tm:fiber

Paper 7914-57 of Conference 7914
Date: Thursday, 27 January 2011
Time: 11:40 AM – 12:00 PM

Author(s): Robert A. Sims, Pankaj Kadwani, Lawrence Shah, Martin C. Richardson, CREOL, The College of Optics and Photonics, Univ. of Central Florida (United States)
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We describe the generation and amplification of femtosecond 2 μm pulses in Tm:fiber. Mode-locked pulses at ~ 2 μm were generated in a Tm:fiber oscillator using a single-walled carbon nanotube saturable absorber. A ring cavity was core pumped at 1.55 μm and stable mode-locking was achieved at a repetition rate of 87 MHz. Pulses exhibited energies of 40 pJ and spectral bandwidths ~12 nm. Autocorrelation pulse width measurements indicated bandwidth limited pulses of ~350 fs duration. This oscillator was used to seed a Tm:fiber amplifier with either free space or fiber coupling. Effects of dispersion and pulse amplification are reported.

Processing and transparency of polycrystalline yttrium aluminum garnet (YAG) fiber for optical applications

Paper 7912-66 of Conference 7912
Date: Thursday, 27 January 2011
Time: 11:50 AM – 12:10 PM

Author(s): Hyun Jun Kim, UES, Inc. (United States); Geoff E. Fair, Air Force Research Lab. (United States); Heedong Lee, Kristin A. Keller, Triplicane A. Parthasarathy, UES, Inc. (United States); Randall S. Hay, Air Force Research Lab. (United States)
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Polycrystalline Yttrium Aluminum Garnet (YAG) fibers were prepared for optical applications. Green fibers were prepared with extrusion process and transparencies of the fibers were visually compared with that of the single crystal fiber. In this presentation, our recent advancement in fiber processing will be discussed.

Novel fibers for next generation parametric devices

Paper 7959-25 of Conference 7959
Date: Thursday, 27 January 2011
Time: 12:40 PM – 1:10 PM

Author(s): Hugo L. Fragnito, Jose Amilton Mores, Jr., Univ. Estadual de Campinas (Brazil); Lucas Heitzmann Gabrielli, Cornell Univ. (United States); Hugo E. Hernandez-Figueroa, Univ. Estadual de Campinas (Brazil)
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Special fibers designed for broadband and efficient fiber optical parametric amplifiers (FOPA) are challenging because they require small values of the high (fourth and sixth) order dispersion coefficients and low fluctuations of these parameters along the fiber length. We discuss on new designs of conventional (cylindrically symmetric) and structured (photonic crystal) fibers for FOPAs that are robust against fabrication fluctuations.

Operational condition of direct single-mode-fiber coupled FSO terminal under strong atmospheric turbulence

Paper 7923-24 of Conference 7923
Date: Thursday, 27 January 2011
Time: 2:20 PM – 2:40 PM

Author(s): Yoshinori Arimoto, National Institute of Information and Communications Technology (Japan)
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This paper discusses the operational condition for direct single-mode-fiber-coupling FSO terminals under the various adverse weather conditions, such as strong atmospheric turbulences and rains. A good correlation between the scintillation index of the intensities of beacon receiving power and the signal fading depth has been observed, which allows us to predict the signal link quality based on the beacon scintillation index provided by the classical scintillation theory and concludes that the scintillation index for the beacon beam should be less than 0.1. This paper also reports the effect of performance enhancements provided by the new adaptive controller for the stable and robust terminal operation.

Design, fabrication, and characterization of acoustic antiguiding large core YDFAs

Paper 7914-62 of Conference 7914
Date: Thursday, 27 January 2011
Time: 3:00 PM – 3:20 PM

Author(s): William E. Torruellas, Michael C. Gross, Michael L. Dennis, The Johns Hopkins Univ. (United States); Mansoor Alam, Kevin F. Farley, Victor Khitrov, Kanishka Tankala, Nufern (United States)
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We have achieved an improvement of a factor 6-7 of the Stimulated-Brillouin-Scattering (SBS) threshold large core YDFA with of 25m core diameter operating in single transverse mode and showing excellent beam quality, M2<1.5. Our design methodology shows the ability to readily increase this performance to values in excess of 10x compared to those achieved in fibers with step index profiles in both the optical and the acoustic domains.

Innovative laser based solar cell scribing

Paper 7921-39 of Conference 7921
Date: Thursday, 27 January 2011
Time: 4:55 PM – 5:20 PM

Author(s): Bruno Frei, Stefan Schneeberger, Reiner Witte, Solneva SA (Switzerland)
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The continuous growth of the photovoltaic market is directly dependant on the manufacturing costs for solar cells. Lasers are excellent and innovative tools for highly efficient processes with impressive accuracy. In combination with fast and precise motion systems they lead to best cost of ownership. This article presents an innovative solution for thin Si film laser scribing. A combination of a new glass holding technique, a fast and precise motion system and fiber lasers guarantee short setup and down times, high resolution and reproducibility for P1, P2, P3. The reduction of the dead zone and the improved efficiency are the technical and economic benefits of this solution.

Innovative laser based solar cell scribing

Paper 7920-39 of Conference 7920
Date: Thursday, 27 January 2011
Time: 4:55 PM – 5:20 PM

Author(s): Bruno Frei, Stefan Schneeberger, Reiner Witte, Solneva SA (Switzerland)
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The continuous growth of the photovoltaic market is directly dependant on the manufacturing costs for solar cells. Lasers are excellent and innovative tools for highly efficient processes with impressive accuracy. In combination with fast and precise motion systems they lead to best cost of ownership. This article presents an innovative solution for thin Si film laser scribing. A combination of a new glass holding technique, a fast and precise motion system and fiber lasers guarantee short setup and down times, high resolution and reproducibility for P1, P2, P3. The reduction of the dead zone and the improved efficiency are the technical and economic benefits of this solution.

Optic axis determination by fiber-based polarization-sensitive swept-source optical coherence tomography

Paper 7889-31 of Conference 7889
Date: Tuesday, 25 January 2011
Time: 9:00 AM – 9:15 AM

Author(s): Zenghai Lu, Deepa K. Kasaragoda, Stephen J. Matcher, The Univ. of Sheffield (United Kingdom)
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Fiber-based swept-source PS-OCT continuous source-polarization modulation (PS-SS-OCT) is used to determine 3-D optic axis of birefringent biological tissues. A theoretical and experimental analysis of the effect of the sampling fiber on determination of optic axis orientation using a proposed definition based on the orientation of the eigenpolarization ellipse experimentally confirms that this algorithm only works correctly for some settings of the sampling fiber. A proposed algorithm based on the angle between Stokes vectors on the Poincare sphere is confirmed to work for all settings of the sampling fiber.

Fiber-based combined optical coherence and multiphoton microscopy

Paper 7892-9 of Conference 7892
Date: Saturday, 22 January 2011
Time: 11:30 AM – 11:50 AM

Author(s): Gangjun Liu, Zhongping Chen, Beckman Laser Institute and Medical Clinic (United States)
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This manuscript demonstrates a multimodal imaging system which combined multiphoton microscopy (MPM) imaging modality with Fourier domain (FD) optical coherence microscopy (OCM) modality. The system used a single fiber femtosecond laser as the light source for both MPM and OCM modality. The femtosecond fiber laser has a central wavlength of 1.03um and a pulse width of 120fs. The systems used fiber based devices for both MPM and OCM. The MPM and OCM shared the same excitation light path. The excitation light was delivered with the core of a dual-clad fiber. The MPM signal was collected by the clad of the dual-clad fiber. The FD OCM used a home-built InGaAs detector array spectrometer.

Novel WDM to OTDM wavelength converter system for transmission of discrete sampling spectrum in single wavelength channel

Paper 7936-22 of Conference 7936
Date: Sunday, 23 January 2011
Time: 5:50 PM – 6:10 PM

Author(s): Tianxin Yang, Changle Wang, Junlong Wang, Chunfeng Ge, Mei Sang, Tianjin Univ. (China)
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A novel WDM-to-OTDM conversion system which has a simple setup is proposed. The system is a type of fiber loop consisting of an optical single-side-band (SSB) modulator that is driven by a RF signal source at 10 GHz (0.08 nm), a fiber circulator, a fiber coupler, a fiber amplifier and an ultra-narrowband high reflectivity fiber Bragg grating (FBG). A frame multi-wavelength signals λn =λ1+(n-1)×0.08 nm are inputted into the system where all of them are conversed to the single wavelength λ1 and exit from the system one by one after the (n-1) optical round loop times delay.

Nano-watt active fiber devices in electro-optic crystallized glass

Paper 7934-1 of Conference 7934
Date: Tuesday, 25 January 2011
Time: 10:30 AM – 11:00 AM

Author(s): Takumi Fujiwara, Tohoku Univ. (Japan)
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Fabrication of newly developed fiber-type devices with hybrid structure of crystallized glass and demonstration of light controlling with the electro-optic (EO) effect based on second-order optical nonlinearity for the future optical communication will be presented. Research collaboration with the Asahi Glass Co. has been performed to achieve "active" fiber devices such as variable optical attenuator and polarization controller involved in the glass fiber networks with huge number of access lines. We have succeeded in developments of novel glass ceramics with large second-order optical nonlinearity, new processing for space-selective laser-crystallization, and advanced fiber-type devices with the glass-crystal hybrid structure. The active fiber-type devices have exhibited the electro-optically modulations of intensity and phase in light propagation. In addition, the most impressive property from this device is the ultra-low electrical power dissipation, nano-wattage (nW), for EO operations. This is an important requirement for the future optical communication system in the world, since the "nano-watt devices" will save the energy crisis caused by the millions of usage in active optical components.

Blood interference in fiber-optical based fluorescence guided resection of glioma using 5-aminolevulinic acid

Paper 7883E-98 of Conference 7883E
Date: Saturday, 22 January 2011
Time: 9:30 AM – 9:50 AM

Author(s): Neda Haj-Hosseini, Linköping Univ. (Sweden); Shannely Lowndes, Fachhochschule beider Basel (Switzerland); Johan Richter, Karin Wårdell, Linköping Univ. (Sweden)
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In fiber-optical based fluorescence spectroscopy during brain tumor resection, blood interference is frequently observed. Usually a considerable amount of data is discarded as the corresponding spectrum cannot be reliably quantified. In this study, a fiber-optical based fluorescence spectroscopy system with a laser excitation light of 405 nm was used during fluorescence guided brain tumor resection using 5-aminolevulinic acid (5-ALA). The blood interference pattern in the fluorescence spectrum was studied in 15 patients and compared to the operation situation modeled in the laboratory. The blood, when not blocking the optical signal totally, weakens the collected fluorescence intensity and leaves traces of oxy and de-oxy hemoglobin in addition to some other chromophores in the brain fluorescence spectrum.

Proper laser-fiber sweeping angle for the effective tissue vaporization using XPSTM with MoXyTM fiber

Paper 7883B-55 of Conference 7883B
Date: Saturday, 22 January 2011
Time: 4:30 PM – 4:50 PM

Author(s): Woo Jin Ko, Columbia Univ. Medical Ctr. (United States) and National Health Insurance Corp. Ilsan (Korea, Republic of); Hyun Wook Kang, American Medical Systems Holdings, Inc. (United States); Danop Rajabhandharaks, Douglas G. Stinson, American Medical Systems, Inc. (United States); Benjamin B. Choi, Weill-Cornell Univ. Medical Ctr. (United States) and Metropolitan Urology (United States)
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We identify the optimal fiber sweeping angle to maximize tissue vaporization efficiency using XPSTM with MoXyTM fiber. Porcine kidney was prepared. Ten tissue specimens were used for each angle. The power was fixed at 120W. The fiber sweeping speed and treatment speed were 0.5 sweep/sec and 2mm/sec. The sweeping angle greater than 60 is less effective. The results at 0 and 60 degree were not statistically significant. The result at 0 degree is worse than 15, 30 degree. The optimal SA for tissue vaporization is 15, 30 degree.

The optimized laser fiber sweeping speed(SS) for the effective tissue vaporization at various power levels using XPSTM with MoXyTM fiber

Paper 7883B-56 of Conference 7883B
Date: Saturday, 22 January 2011
Time: 4:50 PM – 5:10 PM

Author(s): Woo Jin Ko, Columbia Univ. Medical Ctr. (United States) and National Health Insurance Corp. Ilsan Hospital (Korea, Republic of); Hyun Wook Kang, American Medical Systems Holdings, Inc. (United States); Danop Rajabhandharaks, Douglas G. Stinson, American Medical Systems, Inc. (United States); Benjamin B. Choi, Weill-Cornell Univ. Medical Ctr. (United States)
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We investigated the laser fiber sweeping speed for the effective tissue vaporization and the difference of the ablation volume at different power levels. Porcine kidney was used for tissue sample. The investigated power levels were at 120W and 180W. The maximum ablation rate according to SS was shown at 0.5 sweep/sec in both power levels. The effective SS for tissue vaporization is 0.5 and 1 sweep/sec. The result showed the same trend at the two power levels and SS at 0.5 sweep/sec was almost twice effective for tissue vaporization at 180W compared to 120W.

Extended-range multiwavelength all-fiber interferometer

Paper 7894-27 of Conference 7894
Date: Sunday, 23 January 2011
Time: 8:40 AM – 9:00 AM

Author(s): Anil Prabhakar, Abhijeet A. Kulkarni, Shanti Bhattacharya, Indian Institute of Technology Madras (India)
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The all fiber interferometer (AFI) discussed in this paper is a wavelength multiplexed Michelson's interferometer. The use of a mutli-wavelength fibre ring laser allows us to extend the measurement range of the instrument. The paper discusses the design procedure for a low cost, compact AFI and its associated electronic control. We have successfully measured a height of 423 nm for a 420 nm structure with one wavelength and a height of 95 nm for a 100 µm structure with two wavelengths, while a third wavelength was used to stabilize the interferometer against environmental fluctuations.

Polarization attributes of stimulated Brillouin scattering slow light in fiber

Paper 7949-9 of Conference 7949
Date: Sunday, 23 January 2011
Time: 11:25 AM – 11:50 AM

Author(s): Avi Zadok, Moshe Tur, Avishay Eyal, Tel Aviv Univ. (Israel); Luc Thevenaz, Ecole Polytechnique Fédérale de Lausanne (Switzerland)
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Course: Tissue Optics

Date: Sunday, 23 January 2011
Time: 1:30 PM – 5:30 PM

Instructor(s): Steven L. Jacques, OHSU (United States)
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This course outlines the principles of light transport in tissues that underlie design of optical measurement devices and laser dosimetry for medicine. Topics include radiative transport in turbid tissues, the optical properties of tissues, modeling techniques for light transport simulation in tissues, analysis of reflectance and fluorescence spectra measured in turbid tissues by topical and imbedded optical fiber devices, video techniques, and criteria involved in establishing laser dosimetry protocols. Lessons are illustrated using case studies of optical fiber devices, video imaging techniques, and design of therapeutic laser protocols.

Slow light in fiber Bragg gratings

Paper 7949-13 of Conference 7949
Date: Sunday, 23 January 2011
Time: 1:55 PM – 2:20 PM

Author(s): Michel J. F. Digonnet, He Wen, Shanhui Fan, Stanford Univ. (United States)
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Retardation of Henle's fiber layer measured with polarization-sensitive optical coherence tomography

Paper 7885-54 of Conference 7885
Date: Sunday, 23 January 2011
Time: 4:45 PM – 5:00 PM

Author(s): Donald T. Miller, Qiang Wang, Jason Besecker, Weihua Gao, Sangyeol Lee, Omer P. Kocaoglu, Ravi S. Jonnal, Indiana Univ. (United States); Barry Cense, Utsunomiya Univ. (Japan)
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The structured organization of Henle's fiber layer is well known to exhibit birefringence, which has been suggested as a sensitive indicator of retinal disease. To investigate this possibility, we have developed a method based on polarization-sensitive optical coherence tomography that measures the double pass phase retardation (DPPR) of Henle's fiber layer. We successfully measured this layer's DPPR in three patient groups: healthy and young; healthy and old; and diagnosed with glaucoma. In the healthy subjects, maxima DPPR reached 15°-25° and occurred near the rim of the fovea pit. In the glaucoma patients, DPPR was found reduced.


Phase modulated radio-over-fiber systems: linearization and photonic downconversion

Paper 7936-21 of Conference 7936
Date: Sunday, 23 January 2011
Time: 5:20 PM – 5:50 PM

Author(s): Thomas E. Murphy, Univ. of Maryland, College Park (United States)
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Although most radio-over-fiber (RoF) systems use intensity modulation to impose the microwave signal onto an optical carrier, there is a growing interest in using phase modulation instead. Compared to intensity modulators, phase modulators not only eliminate the need for active bias control circuitry at the transmitter, but also offer lower insertion loss and higher optical power handling capability. Despite these advantages, phase modulation systems have yet to be widely accepted, in part because phase modulated optical signals are harder to detect at the receiver. We describe our ongoing efforts to develop new types of phase-modulated RoF communication systems that offer the advantages of linearized performance for extended dynamic range, together with optical photonic downconversion at the receiver.

Experimental investigation of intracavity fiber array beam combining

Paper 7913-19 of Conference 7913
Date: Sunday, 23 January 2011
Time: 5:30 PM – 5:50 PM

Author(s): Sergey A. Dimakov, S. I. Klimentiev, Vladimir V. Lyubimov, A. Yu. Rodionov, Dmitrii I. Zhuk, S.I. Vavilov State Optical Institute (Russian Federation)
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The report introduces the results of experimental studies of intracavity fiber array beam combining. For the first time it was experimentally demonstrated generation of Hermite- Gaussian anti-symmetric mode TEM30 in stable super resonator for coherent combination of beams of four fiber amplifiers. Maximum number of phasing fiber channels by means of suggested method has been estimated.

Removal of brain tissue by Tm-Fiber laser

Paper 7901-20 of Conference 7901
Date: Sunday, 23 January 2011
Time: 5:30 PM – 5:45 PM

Author(s): Burcu Tunç, Murat Gülsoy, Bogaziçi Üniv. (Turkey)
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The aim of the study was to investigate the thermal effects of the 1940-nm Tm-fiber laser on the dead brain tissue. 4-5 mm coronal sections were taken from lamb brains. Tm-fiber laser was applied at the back (cortical) and below the cortex (subcortical) of this slices with 0.5 mm distance. Lasers were applied in both continuous and pulsed modes. By calculating ablation efficiency (100xablation/calculation radius) the aproppriate laser doses were determined for both cortical and subcortical tissue. The maximum ablation efficiency for cortical tissue in continuous mode was 200 mW and 600 mW and in pulsed mode was 600 mW and for subcortical tissue maximum ablation efficiency was found 600 mW in both continuous mode and pulsed mode.

Material micromachining using bursts of high-repetition rate picosecond pulses from a fiber laser source

Paper 7914-3 of Conference 7914
Date: Monday, 24 January 2011
Time: 9:10 AM – 9:30 AM

Author(s): Alain Cournoyer, Mathieu Drolet, Louis Desbiens, Dany Lemieux, Martin Briand, Yves Taillon, INO (Canada)
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In this paper, we demonstrate the benefits of using bursts of picosecond pulses for material micromachining and compare the results with those obtained when using a nanosecond source with similar pulse energy, pulse width and pulse shape. Micro-milling experiments were performed on silicon and fused silica. For silicon, we show that the maximum material removal efficiency can be increased by more than 10% when using bursts of picosecond pulses with respect to nanosecond pulses with similar energy per pulse. We also demonstrate the feasibility of laser micro-milling using bursts of picosecond pulses, taking advantage of the peak power that is significantly higher within a picosecond burst as compared to a nanosecond pulse of the same energy, shape and width.

Dynamic pulsing of a MOPA fiber laser for processing of thermally sensitive materials

Paper 7914-95 of Conference 7914
Date: Monday, 24 January 2011
Time: 9:30 AM – 9:50 AM

Author(s): Sami T. Hendow, José R. Salcedo, Paulo T. Guerreiro, João M. Sousa, Multiwave Photonics (Portugal)
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A MOPA pulsed fiber laser is configured to produce very fast bursts of nanosecond pulses, at any pulse repetition frequency from single shot to 500 kHz. Each pulse burst is composed of any sequence of stored pulses of arbitrary pulse widths and separation. Pulse bursts are shown with pulse sequences and separation that offer high peak power, as compared to an equivalent single pulse of similar pulse energy and width. A group of 1064nm pulses, each is 10ns wide and separated by 50ns, is applied to thermally sensitive materials and the results are compared to those by a single pulse of equivalent pulse energy. Benefits include reduced HAZ and controlled ablation and oxidation of materials.

Endovenous laser ablation with TM-fiber laser

Paper 7897-6 of Conference 7897
Date: Monday, 24 January 2011
Time: 9:50 AM – 10:10 AM

Author(s): Meral F. Somunyudan, Nermin Topaloglu, Bogaziçi Üniv. (Turkey); Mehmet Ü. Ergenoglu, Yeditepe Univ. (Turkey); Murat Gülsoy, Bogaziçi Üniv. (Turkey)
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Endovenous Laser Ablation (EVLA) has become more popular than classical surgial treatment in the management of varicose veins in recent years. Endovenous Laser ablation is safer, more efficient and minimally invasive than classical surgery when the necessity of general anaesthesia, postoperative events and reccurance rate of the classical surgery is considered. Since endovenous laser ablation is new technology, the optimum parameters are still under investigation. The aim of this paper is to compare 1940-nm wavelength with 980-nm wavelength in the management of varicose veins at different power. After laser application, remarkable shrinkage and narrowing in outer and iner diameter was observed.

Coherent anti-Stokes Raman scattering microspectroscopy based on a compact Er:fiber laser

Paper 7903-30 of Conference 7903
Date: Monday, 24 January 2011
Time: 11:01 AM – 11:13 AM

Author(s): Romedi Selm, Martin Winterhalder, Andrea M. Nagy, Andreas Zumbusch, Günther Krauss, Tobias Hanke, Alexander Sell, Alfred Leitenstorfer, Univ. Konstanz (Germany)
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Coherent anti-Stokes Raman scattering (CARS) microspectroscopy is a novel type of vibrational microscopy. To improve the performance and ease of use of existing systems a two-color picosecond Er:fiber laser has been developed. This system provides narrowband pump and Stokes pulses giving access to vibrational resonances from 1150 cm−1 to 3800 cm−1. Here we present images of a variety of living cells, for example yeast and adipocytes. Minor changes to the laser system allow for broadband background-free CARS signal generation.

Nerve fiber recruitment in the context of hybrid neural stimulation

Paper 7883G-148 of Conference 7883G
Date: Monday, 24 January 2011
Time: 1:50 PM – 2:10 PM

Author(s): Austin R. Duke, Vanderbilt Univ. (United States); Hui Lu, Michael W. Jenkins, Case Western Reserve Univ. (United States); Melanie A. Gault, Vanderbilt Univ. (United States); Jeff McManus, Hillel J. Chiel, Case Western Reserve Univ. (United States); E. Duco Jansen, Vanderbilt Univ. (United States)
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Recently, hybrid neural stimulation combining electrical and optical techniques was shown to reduce optical stimulation thresholds as much as 3-fold while maintaining spatial selectivity; thus overcoming the risk of thermally-induced tissue damage associated with optical stimulation and the fundamental lack of spatial specificity associated with electrical stimulation. To further develop this technology, we need to better understand the spatial superposition of the electrical and optical stimuli. We will present our investigation of the recruitment of select neurons using infrared neural stimulation and electrical stimulation in the context of developing the hybrid stimulation paradigm.

A novel multiple port side pump couplers for high-power fiber lasers

Paper 7914-13 of Conference 7914
Date: Monday, 24 January 2011
Time: 2:10 PM – 2:40 PM

Author(s): Yoav Sintov, Avraham Meir, Yaakov Glick, Shaul Pearl, Soreq Nuclear Research Ctr. (Israel)
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Fiber optic endomicroscope for CARS imaging

Paper 7903-39 of Conference 7903
Date: Monday, 24 January 2011
Time: 2:21 PM – 2:33 PM

Author(s): Yuying Zhang, The Johns Hopkins Univ. (United States); Ruben Zadoyan, Newport Corp. (United States); Xingde Li, The Johns Hopkins Univ. (United States)
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Fiber-laser-pumped CW OPO for red, green, blue laser generation

Paper 7912-5 of Conference 7912
Date: Monday, 24 January 2011
Time: 3:30 PM – 4:00 PM

Author(s): Yen-Yin Lin, Yen-Chieh Huang, National Tsing Hua Univ. (Taiwan)
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We report a CW, watt-level, red, green, and blue (RGB) laser pumped by a low-cost multi-longitudinal-mode Yb-fiber laser at 1064 nm. A singly resonant optical parametric oscillator at 1560 nm contains two intracavity sum-frequency generators for red and blue laser generations. An extracavity second harmonic generator converts the residual pump power into green laser radiation. At 25-W pump power, the laser generated 3.9, 0.5, and 0.5 W at 633, 532, and 450 nm, respectively. The multimode pump laser offers large temperature bandwidths for the RGB laser radiations, because different spectral components of the pump are used in different wavelength converters.

Fiber-laser-pumped CW OPO for red, green, blue laser generation

Paper 7917-5 of Conference 7917
Date: Monday, 24 January 2011
Time: 3:30 PM – 4:00 PM

Author(s): Yen-Yin Lin, Yen-Chieh Huang, National Tsing Hua Univ. (Taiwan)
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We report a CW, watt-level, red, green, and blue (RGB) laser pumped by a low-cost multi-longitudinal-mode Yb-fiber laser at 1064 nm. A singly resonant optical parametric oscillator at 1560 nm contains two intracavity sum-frequency generators for red and blue laser generations. An extracavity second harmonic generator converts the residual pump power into green laser radiation. At 25-W pump power, the laser generated 3.9, 0.5, and 0.5 W at 633, 532, and 450 nm, respectively. The multimode pump laser offers large temperature bandwidths for the RGB laser radiations, because different spectral components of the pump are used in different wavelength converters.

3D modeling of noncontact fiber-based approach for time-resolved diffuse optical tomography

Paper 7896-35 of Conference 7896
Date: Monday, 24 January 2011
Time: 3:40 PM – 4:00 PM

Author(s): Farouk Nouizi, Murielle Torregrossa, Olivier Genevaux, Renee Chabrier, Patrick Poulet, Univ. de Strasbourg (France)
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We developed time-resolved diffuse optical tomography system that enables performing noncontact 3D-DOT measurements of irregular shapes which is appropriate for small animal imaging. To retrieve the surface mesh, a noncontact holographic setup using a sensor and an XY optical scanning system was used. We present a noncontact modeling approach that consists on computing the temporal intensity distribution of diffused photons detected taking into account the free space propagation from or to the fibers disposed around the animal at some distance from its surface. The optimization was performed once on the moments then on the entire points of the temporal profiles

Experimental demonstration of light transmission property through a tapered fiber embedded in scattering nanoparticles

Paper 7913-34 of Conference 7913
Date: Monday, 24 January 2011
Time: 4:30 PM – 4:50 PM

Author(s): Hideki Fujiwara, Takumi Ikeda, Keiji Sasaki, Hokkaido Univ. (Japan)
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To achieve mode control even in random structures, we have numerically proposed a simple structure for manipulating resonant conditions, in which a defect region without scatterers is deliberately made. For the experimental verification of the proposed method, we examined light transmission properties of a tapered fiber (waveguide defect), which waist was partly covered by ZnO nanoparticles (random structure). From the results, transmission band was observed and that was well corresponding to the transmission dip of a ZnO nanoparticle film, which behaviors qualitatively matched to the numerical results.

Enhancing the sensitivity of interometer using fiber resonators

Paper 7949-40 of Conference 7949
Date: Monday, 24 January 2011
Time: 4:50 PM – 5:15 PM

Author(s): Yundong Zhang, Jinfang Wang, Xuenan Zhang, Hao Wu, Jing Zhang, Yuanxue Cai, Ping Yuan, Harbin Institute of Technology (China)
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Ultra-high brightness, wavelength-stabilized, kW-class fiber coupled diode laser

Paper 7918-41 of Conference 7918
Date: Monday, 24 January 2011
Time: 5:10 PM – 5:30 PM

Author(s): Robin K. Huang, Bien Chann, John D. Glenn, TeraDiode, Inc. (United States)
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If accepted, this abstract text will be published prior to the meeting in online or printed programs promoting the conference. Please submit only 100-word abstracts suitable for early release. TeraDiode, Inc. has produced a fiber-coupled direct diode laser with a power level of 1,040 W from a 200 µm core diameter, 0.18 numerical aperture (NA) output fiber. This performance corresponds to a Beam Parameter Product (BPP) of 18 mm-mrad and is to our knowledge the lowest BPP kW-class direct diode laser yet reported. The laser has been used in a laser welding demonstration.

Quantitative analysis of collagen fiber orientation in with two-dimensional fast Fourier transform

Paper 7885-62 of Conference 7885
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Wen Lo, National Taiwan Univ. (Taiwan) and National Cheng Kung Univ. (Taiwan); Chiu-Mei Hsueh, Wei-Liang Chen, National Taiwan Univ. (Taiwan); Shean-Jen Chen, National Cheng Kung Univ. (Taiwan); Hsin-Yuan Tan, Chang Gung Memorial Hospital (Taiwan) and Chang Gung Univ. (Taiwan); Chen-Yuan Dong, National Taiwan Univ. (Taiwan)
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The purpose of this study is to investigate the structural features of corneal stroma by second harmonic generation (SHG) microscopy. Since collagen can be induced to generate strong second harmonic generation (SHG) signal, multiphoton excitation provide direct visualization of collagen orientation within corneal stroma. In this work, we collected both forward and backward SHG signals at different depth across the cornea specimens. The SHG images are later analyzed with 2D fast Fourier transform (2D FFT) to obtain the distribution collagen fiber orientations. We found that the aspect ratio obtained from the 2D FFT analysis can be used for the quantitative determination of fiber orientation and that this approach may be used for the diagnosis of pathological corneas.

Ultra-high-speed fiber-based polarization sensitive optical coherence tomography

Paper 7889-30 of Conference 7889
Date: Tuesday, 25 January 2011
Time: 8:45 AM – 9:00 AM

Author(s): Erich Götzinger, Michael Pircher, Tilman Schmoll, Harald Sattmann, Stefan Zotter, Teresa Torzicky, Marco Bonesi, Rainer A. Leitgeb, Christoph K. Hitzenberger, Medizinische Univ. Wien (Austria)
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We demonstrate an ultra high speed fiber based polarization sensitive spectral domain optical coherence tomography system, using two ultra high speed CMOS line scan cameras. With this system an A-scan rate of up to 200 kHz is possible. The system is based on polarization maintaining fibers and retrieves the backscattered intensity, birefringence and optic axis orientation with only one A-scan per measurement location. To demonstrate the performance of our system we present images of the fovea and the optic nerve head of a healthy human retina. Additionally we show images of intensity and retardation averaged over 30 B-scans.

High-average power second harmonic generation of femtosecond fiber lasers

Paper 7914-27 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 10:20 AM – 10:40 AM

Author(s): Steffen Hädrich, Jan Rothhardt, Tino Eidam, Thomas Gottschall, Jens Limpert, Friedrich-Schiller-Univ. Jena (Germany); Andreas Tünnermann, Friedrich-Schiller-Univ. Jena (Germany) and Fraunhofer Insitute for Applied Optics and Precision Engineering (Germany)
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Second harmonic generation of a high average power, high energy femtosecond Yb doped fiber chirped pulse amplifier is presented at various repetition. After two pre-amplification stages an 80 cm long rod-type PCF with a core diameter of 100 µm is used to extract 70 µJ. Compression yields 450 fs, 50 µJ pulses. Second harmonic generation is achieved in a 500 µm thick BBO crystals. The conversion efficiency of the second harmonic generation remained almost constant at ~50 % for all repetition rates and average power levels. At 4.08 MHz the highest average power of 129 W at 520 nm was achieved.

Photonic devices for next-generation broadband fiber access networks

Paper 7958-1 of Conference 7958
Date: Tuesday, 25 January 2011
Time: 11:30 AM – 12:00 PM

Author(s): Leonid G. Kazovsky, She-Hwa Yen, Shing-Wa Wong, Stanford Univ. (United States)
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Consumers expect substantial benefits from next-generation optical access networks including a dedicated high-QoS access to high bit rates and substantially better availability and reliability. Network operators have their own expectations including reduced total cost of ownership, lower energy consumption, better flexibility and improved efficiency. To satisfy these (sometimes, conflicting) demands, new technologies and devices will be needed. This talk will describe our research toward defining, researching and developing novel photonic devices that will be needed for next-generation optical access networks.

Photonic devices for next-generation broadband fiber access networks

Paper 7959-1 of Conference 7959
Date: Tuesday, 25 January 2011
Time: 11:30 AM – 12:00 PM

Author(s): Leonid G. Kazovsky, She-Hwa Yen, Shing-Wa Wong, Stanford Univ. (United States)
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Consumers expect substantial benefits from next-generation optical access networks including a dedicated high-QoS access to high bit rates and substantially better availability and reliability. Network operators have their own expectations including reduced total cost of ownership, lower energy consumption, better flexibility and improved efficiency. To satisfy these (sometimes, conflicting) demands, new technologies and devices will be needed. This talk will describe our research toward defining, researching and developing novel photonic devices that will be needed for next-generation optical access networks.

Photonic devices for next-generation broadband fiber access networks

Paper 7960-1 of Conference 7960
Date: Tuesday, 25 January 2011
Time: 11:30 AM – 12:00 PM

Author(s): Leonid G. Kazovsky, She-Hwa Yen, Shing-Wa Wong, Stanford Univ. (United States)
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Consumers expect substantial benefits from next-generation optical access networks including a dedicated high-QoS access to high bit rates and substantially better availability and reliability. Network operators have their own expectations including reduced total cost of ownership, lower energy consumption, better flexibility and improved efficiency. To satisfy these (sometimes, conflicting) demands, new technologies and devices will be needed. This talk will describe our research toward defining, researching and developing novel photonic devices that will be needed for next-generation optical access networks.

Carbon nanotubes coated fiber optic ammonia gas sensor

Paper 7941-22 of Conference 7941
Date: Tuesday, 25 January 2011
Time: 11:40 AM – 12:00 PM

Author(s): Sellaperumal Manivannan, Loukkose R. Shobin, Aruppukottai M. Saranya, Balusamy Renganathan, Dillibabu Sastikumar, National Institute of Technology, Tiruchirappalli (India); Kyu Chang Park, Kyung Hee Univ. (Korea, Republic of)
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We report, intrinsic fiber optic carbon nanotubes coated sensor for the detection of ammonia gas at room temperature. Multimode step index polymethyl methacrylate (PMMA) optical fiber passive cladding is partly replaced by an active coating of purified and dispersed single and multi-walled carbon nanotubes following the dip coating technique and the reaction with ammonia is studied by measuring the change in output intensity from the optical fiber for various ammonia gas concentrations in the range 0-500 ppm in step of 50 ppm. The sensitivity is calculated for different wavelengths in the range 200-1000 nm for both single and multi-walled nanotubes coated fibers. The sensitivities are found to be 0.22 and 0.21 for single-walled (average diameter 1.3 nm, ~85 wt.%) and multi-walled (average diameter 10-15 nm, ~95 wt.%) CNTs respectively. The role of diameter and purity of CNTs towards the ammonia sensing is studied and the results will be discusse

Towards integrated photonic quantum technologies with fiber-integrated single photon emitters

Paper 7943-37 of Conference 7943
Date: Tuesday, 25 January 2011
Time: 1:50 PM – 2:20 PM

Author(s): Oliver Benson, Tim Schröder, Andreas Schell, Thomas Aichele, Günther Kewes, Michael Barth, Humboldt-Univ. zu Berlin (Germany)
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On-chip photonic quantum circuits are a promising candidate to realize linear optical networks [1]. Yet the small-scale integration of a single photon source has not been shown. We demonstrate a fiber integrated single photon source that could be coupled to the on-chip waveguides. Fiber integration is realized by near-field coupling of a single N-V centre in a nanodiamond to the modes of a photonic crystal fiber. Collection efficiency reaches that of an air objective with a numerical aperture of n=0.85. Direct coupling out of the fiber to the on chip waveguides would allow improved performance, miniaturization, and scalability. [1] Politi et al., SCIENCE, 320, 647

Semiresonant Lissajous scan of a fiber-cantilever scanning endoscope catheter for stable OCT imaging

Paper 7889-45 of Conference 7889
Date: Tuesday, 25 January 2011
Time: 2:30 PM – 2:45 PM

Author(s): Sucbei Moon, Sang-Won Lee, Marc Rubinstein, Brian J. Wong M.D., Zhongping Chen, Beckman Laser Institute and Medical Clinic (United States)
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Semi-resonant Lissajous scan with a compact fiber-cantilever scanning catheter is presented as a new operation scheme for stable OCT endoscopy imaging. The resonance frequency was decreased to 63 Hz in a favorable scan frequency range by attaching a weight to the cantilever. To avoid scan instability, driving complexity, and nonlinear effects, the scanner was driven at semi-resonance frequencies out of the resonance peak, but within a frequency range of partial resonance. This technique was evaluated for stable 3D OCT imaging by driving the two axes with slightly different scan frequencies that produce an area-filling Lissajous pattern.



OCT imaging with wavelength-swept active mode locking fiber laser

Paper 7889-51 of Conference 7889
Date: Tuesday, 25 January 2011
Time: 4:30 PM – 4:45 PM

Author(s): Hwidon Lee, Chang-Seok Kim, Myung-Yong Jeong, Pusan National Univ. (Korea, Republic of); Ju-Han Lee, Jae-Hyun Shin, The Univ. of Seoul (Korea, Republic of)
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OCT image is demonstrated with a wavelength-swept active mode locking (AML) fiber laser. Unlike conventional wavelength-swept Fourier domain mode locking (FDML) lasers, this novel laser does not require a tunable wavelength selecting filter in the cavity and, thus, ultra-fast sweeping rate can be achieved over 500 kHz.

A hybrid fiber/solid state regenerative amplifier with tunable pulse widths for satellite laser ranging

Paper 7912-85 of Conference 7912
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Demetrios Poulios, American Univ. (United States); D. Barry Coyle, NASA Goddard Space Flight Ctr. (United States)
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A fiber/solid-state hybrid seeded regenerative amplifier capable of achieving high output energy with tunable pulse widths has been developed. The amplifier is seeded with a fiber-coupled 1064 nm narrowband diode laser modulated by a fiber Mach-Zender electro-optic modulator, enabling continuously tunable seed pulse widths in the 0.2-2.0 ns range. The seed laser pulse energy is amplified from to <10 pJ to ~1.7 mJ after 44 round trips, representing a gain of ~62 dB. When seeded with 200 ps pulses at a 2 kHz repetition rate, the regenerative amplifier produces >2 W of frequency-doubled output.

Er-fiber laser based reference frequency standard for ultra dense WDM networks

Paper 7914-68 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Michal P. Nikodem, Krzysztof M. Abramski, Wroclaw Univ. of Technology (Poland)
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We demonstrate all-fiber passively mode-locked optical frequency comb source at 1560 nm stabilized to the absorption line of the hydrogen cyanide. With reduced cavity length 169 MHz fundamental repetition frequency, 111 fs pulse duration and 44 nm wide (FWHM) optical comb were obtained. Frequency of the optical comb was tied to the frequency stabilized DFB laser diode Absolute stability of the single comb line was measured to be 9e-9 We expect that stability of 1e-10 can be obtained with proposed configuration within the whole comb bandwidth.

Fabrication of pump combiners for high-power fiber lasers

Paper 7914-104 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Guido Perrone, Andrea Braglia, Massimo Olivero, Alessandra Neri, Politecnico di Torino (Italy)
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A custom fabrication procedure to realize pump combiners matched to a wide variety of double-clad fibers used in high power fiber lasers has been developed. Both combiners with and without feedthrough can be fabricated with an improved repeatability thanks to a specific mechanical setup that simplifies placing the fibers in their proper location within the input bundle prior to the tapering and fusion processes. Preliminary results on 7-to-1 and on (6+1)-to-1 combiners are confirming the validity of the proposed approach.

Fiber-coupled multi-kW laser processing head with versatile ring focus module

Paper 7921-32 of Conference 7921
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Roman Niedrig, Oliver Mehl, Björn Wedel, HIGHYAG Lasertechnologie GmbH (Germany)
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Materials processing tasks often require an intensity distribution which differs from a circular-symmetric Gaussian or top-hat profile. A task-optimized intensity distribution may improve processing results, simplifies the setup, or even enables new applications. The proposed multi-kW processing head is generating an annular intensity distribution with adjustable geometry. An additional circular symmetric fold mirror then allows for the manufacture of tubular part welds in a single process step without the need for a scanning optic. The optical design and possible applications will be discussed; emphasis will be given to the influence of laser and fiber parameters to the desired intensity distribution.

Laser cutting of carbon fiber reinforced plastics (CFRP) by UV pulsed laser ablation

Paper 7920-47 of Conference 7920
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Hiroyuki Niino, Ryozo Kurosaki, National Institute of Advanced Industrial Science and Technology (Japan)
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In this paper, we report on the micro-cutting of carbon fiber reinforced plastics (CFRP) by nanosecond-pulsed laser ablation with a diode-pumped solid state (DPSS) UV laser. As a single mode DPSS laser possesses excellent beam quality as well as high pulse repetition rates, the laser beam having a small laser spot size at a high repetition rate is readily available in ambient air by focusing with a simple lens, so that the laser has the capability of dealing with surface micro-cutting on material substrates at a high throughput for manufacturing practices. Well-defined cutting of CFRP which were free of debris and thermal-damages around the grooves, were fabricated by the laser irradiation. The inside wall surface of cutting region indicated that carbon fibers were cut by the laser ablation smoothly. The flexibility of various shapes of the trenches is caused by the feature of laser direct cutting.

Power-equalized multiwavelength Raman fiber laser based on random distributed feedback

Paper 7914-112 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Sergey A. Babin, Institute of Automation and Electrometry (Russian Federation); Atalla E. El-Taher, Paul Harper, Aston Univ. (United Kingdom); Dmitriy V. Churkin, Evgenii V. Podivilov, Institute of Automation and Electrometry (Russian Federation); Juan D. Ania-Castanon, Consejo Superior de Investigaciones Científicas (Spain); Sergei K. Turitsyn, Aston Univ. (United Kingdom)
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We experimentally demonstrate a multiwavelength Raman fiber laser based on multiple fiber Bragg grating reflectors and distributed feedback via Rayleigh backscattering in a ~22 km long optical fiber. Twenty two lasing lines with spacing of ~100 GHz (close to ITU grid) in C-band are generated at Watts power level with 40% efficiency. In contrast to the normal cavity with competition between laser lines, the random distributed feedback (RDFB) cavity exhibits highly stable multiwavelength generation with a power-equalized uniform spectral distribution. The total output power in RDFB cavity appears slightly higher than in normal cavity. Explanation of the effects is provided.

Chip-integrated fiber optics for efficient and scalable ion and atom detection

Paper 7948-15 of Conference 7948
Date: Wednesday, 26 January 2011
Time: 8:00 AM – 8:25 AM

Author(s): Yves Colombe, Aaron P. VanDevender, National Institute of Standards and Technology (United States); Jason Amini, National Institute of Standards and Technology (United States) and Georgia Tech Research Institute (United States); Andrew Wilson, National Institute of Standards and Technology (United States); Tilo Steinmetz, Lab. Kastler Brossel (France) and Max-Planck-Institut fuer Quantenoptik / LMU (Germany); Guilhem Dubois, Roger Gehr, Jürgen Volz, Felix Linke, Lab. Kastler Brossel (France); David Hunger, Ludwig-Maximilians-Univ. München (Germany); Romain Long, Jérôme Estève, Christian Deutsch, Lab. Kastler Brossel (France); Benjamin L. Lev, Univ. of Illinois at Urbana-Champaign (United States); Theodor W. Hänsch, Ludwig-Maximilians-Univ. München (Germany); Jakob Reichel, Lab. Kastler Brossel (France); Dietrich Leibfried, David J. Wineland, National Institute of Standards and Technology (United States)
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The integration of optical fibers to microfabricated ion or atom traps offers many new exciting possibilities. I will present experiments realized with single neutral atoms and Bose-Einstein condensates in the group of Jakob Reichel in Paris, and with ions in the NIST Ion-Storage group in Boulder. These experiments combine fiber Fabry-Perot microcavities and air-clad high numerical aperture fiber optics with microfabricated surface traps.

Developing accurate simulations for high-speed fiber links

Paper 7958-9 of Conference 7958
Date: Wednesday, 26 January 2011
Time: 9:00 AM – 9:20 AM

Author(s): Steven M. Searcy, Andrew J. Stark, Thomas F. Detwiler, Yu-Ting Hsueh, Georgia Institute of Technology (United States); Sorin Tibuleac, ADVA Optical Networking North America, Inc. (United States); Gee-Kung Chang, Stephen E. Ralph, Georgia Institute of Technology (United States)
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Reliable simulations of high-speed fiber optic links are necessary to understand, design, and deploy fiber networks. We detail the efforts within the Georgia Tech 100G Consortium to achieve high absolute accuracy between simulation and experimental performance with a goal of ±0.25 dB for back-to-back configuration, and ±0.5 dB for transmission over multiple spans. We perform these tests for 56 Gb/s (single-polarization) and 112 Gb/s (dual-polarization) DQPSK and coherent QPSK within a 50 GHz DWDM. By developing an accurate model we are able to demonstrate high simulation accuracy for a wide range of OSNR values.

Developing accurate simulations for high-speed fiber links

Paper 7959-9 of Conference 7959
Date: Wednesday, 26 January 2011
Time: 9:00 AM – 9:20 AM

Author(s): Steven M. Searcy, Andrew J. Stark, Thomas F. Detwiler, Yu-Ting Hsueh, Georgia Institute of Technology (United States); Sorin Tibuleac, ADVA Optical Networking North America, Inc. (United States); Gee-Kung Chang, Stephen E. Ralph, Georgia Institute of Technology (United States)
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Reliable simulations of high-speed fiber optic links are necessary to understand, design, and deploy fiber networks. We detail the efforts within the Georgia Tech 100G Consortium to achieve high absolute accuracy between simulation and experimental performance with a goal of ±0.25 dB for back-to-back configuration, and ±0.5 dB for transmission over multiple spans. We perform these tests for 56 Gb/s (single-polarization) and 112 Gb/s (dual-polarization) DQPSK and coherent QPSK within a 50 GHz DWDM. By developing an accurate model we are able to demonstrate high simulation accuracy for a wide range of OSNR values.

Developing accurate simulations for high-speed fiber links

Paper 7960-9 of Conference 7960
Date: Wednesday, 26 January 2011
Time: 9:00 AM – 9:20 AM

Author(s): Steven M. Searcy, Andrew J. Stark, Thomas F. Detwiler, Yu-Ting Hsueh, Georgia Institute of Technology (United States); Sorin Tibuleac, ADVA Optical Networking North America, Inc. (United States); Gee-Kung Chang, Stephen E. Ralph, Georgia Institute of Technology (United States)
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Reliable simulations of high-speed fiber optic links are necessary to understand, design, and deploy fiber networks. We detail the efforts within the Georgia Tech 100G Consortium to achieve high absolute accuracy between simulation and experimental performance with a goal of ±0.25 dB for back-to-back configuration, and ±0.5 dB for transmission over multiple spans. We perform these tests for 56 Gb/s (single-polarization) and 112 Gb/s (dual-polarization) DQPSK and coherent QPSK within a 50 GHz DWDM. By developing an accurate model we are able to demonstrate high simulation accuracy for a wide range of OSNR values.

Advanced methods of quantifying electrospun fiber alignment

Paper 7897-48 of Conference 7897
Date: Wednesday, 26 January 2011
Time: 10:40 AM – 11:00 AM

Author(s): Nicholas J. Schaub, Sean J. Kirkpatrick, Michigan Technological Univ. (United States); Ryan Gilbert, Rensselaer Polytechnic Institute (United States)
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Bidirectional data transmission over multimode fiber using integrated transceiver chips

Paper 7959-6 of Conference 7959
Date: Wednesday, 26 January 2011
Time: 11:00 AM – 11:30 AM

Author(s): Rainer Michalzik, Alexander Kern, Martin Stach, Fernando Rinaldi, Dietmar Wahl, Univ. Ulm (Germany)
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Rate-adaptive modulation and coding for optical fiber transmission systems

Paper 7960-10 of Conference 7960
Date: Wednesday, 26 January 2011
Time: 11:00 AM – 11:30 AM

Author(s): Gwang-Hyun Gho, Joseph M. Kahn, Stanford Univ. (United States)
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Advances in fiber access networks development: efficient resource allocation and cost effective protection

Paper 7959-7 of Conference 7959
Date: Wednesday, 26 January 2011
Time: 1:30 PM – 2:00 PM

Author(s): Jiajia Chen, Lena Wosinska, Royal Institute of Technology (Sweden)
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Passive optical network (PON) is considered as the most promising fiber access network architecture, due to the relatively low deployment cost and high resource efficiency. Thus, this talk will focus on PON deployment and give an overview of our recent results related to dynamic resource allocation in PON and cost efficient reliability performance improvement of fiber access networks. It will be shown that among fiber access network architectures, PON is the one that offers solutions for providing protection at lowest cost. We will conclude with pointing out some selected research topics that are still open and need to be tackled.

Advances in fiber access networks development: efficient resource allocation and cost effective protection

Paper 7958-7 of Conference 7958
Date: Wednesday, 26 January 2011
Time: 1:30 PM – 2:00 PM

Author(s): Jiajia Chen, Lena Wosinska, Royal Institute of Technology (Sweden)
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Passive optical network (PON) is considered as the most promising fiber access network architecture, due to the relatively low deployment cost and high resource efficiency. Thus, this talk will focus on PON deployment and give an overview of our recent results related to dynamic resource allocation in PON and cost efficient reliability performance improvement of fiber access networks. It will be shown that among fiber access network architectures, PON is the one that offers solutions for providing protection at lowest cost. We will conclude with pointing out some selected research topics that are still open and need to be tackled.

Rediscovered dynamics of nonlinear fiber optics: from breathers to extreme localisation

Paper 7917-31 of Conference 7917
Date: Wednesday, 26 January 2011
Time: 1:50 PM – 2:10 PM

Author(s): Bertrand Kibler, Julien Fatome, Christophe Finot, Guy Millot, Univ. de Bourgogne (France); Frederic Dias, Ecole Normale Supérieure de Cachan (France); Goery Genty, Miro Erkintalo, Tampere Univ. of Technology (Finland); Nail Akhmediev, The Australian National Univ. (Australia); John M. Dudley, Univ. de Franche-Comté (France)
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Recent investigations have shown a renewed interest in certain classes of analytical solutions of the Nonlinear Schrödinger equation which, although present in the mathematical literature for 25 years, have been largely overlooked in studies of nonlinear fiber propagation in optics. In this paper we review recent experiments that have shown the power of this analytic approach.

Challenges for fiber lasers in defense applications

Paper 7914-44 of Conference 7914
Date: Wednesday, 26 January 2011
Time: 2:00 PM – 2:30 PM

Author(s): Mark Niece, High Energy Laser Joint Technology Office (United States)
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Fiber lasers in the materials processing market

Paper 7914-45 of Conference 7914
Date: Wednesday, 26 January 2011
Time: 2:30 PM – 3:00 PM

Author(s): David A. Belforte, Photonics Spectra (United States)
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Avoiding fiber nonlinearities by choice of modulation format

Paper 7960-18 of Conference 7960
Date: Wednesday, 26 January 2011
Time: 2:40 PM – 3:00 PM

Author(s): Thomas F. Detwiler, Steven M. Searcy, Andrew J. Stark, Georgia Institute of Technology (United States); Bert E. Basch, Verizon Labs., Inc. (United States); Stephen E. Ralph, Georgia Institute of Technology (United States)
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Nonlinear refraction in fiber optic links is a capacity limiting mechanism, whereby the phase of each propagating signal is modulated by intensity variations of signals in nearby channels. The choice of modulation format plays a primary role in determining the degree of amplitude variation in the channel as well as the robustness to the phase noise impairment that nonlinearities induce. Constant envelope formats avoid fluctuations in the signal, decreasing nonlinear impairments. Alternatively, star-QAM formats enhance the receiver's robustness to phase noise. Using simulated and experimental results we demonstrate the effectiveness of each format in avoiding fiber nonlinearity effects.

Fiber lasers in PV manufacturing

Paper 7914-46 of Conference 7914
Date: Wednesday, 26 January 2011
Time: 3:00 PM – 3:30 PM

Author(s): Bernhard P. Piwczyk, IPG Photonics Corp. (United States)
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Over the past decade lasers have played an increasingly important role in the manufacturing processes for solar cells, starting with wafer cutting and continuing with, fabrication of selective emitters, high speed hole drilling for back contacts, edge isolation, and edge deletion processes. The increasing capabilities of fiber lasers in terns of power, efficiency and reliability open up no possibilities to improve the efficiency of solar cells and the cost of manufacturing. This paper will describe recent work on laser fabrication of semiconductor junctions using high power fiber lasers and reduction of process steps for solar cell fabrication.

Failure and limitations of linear Raman gain approximation for fiber supercontinuum generation modelling

Paper 7917-35 of Conference 7917
Date: Wednesday, 26 January 2011
Time: 3:20 PM – 3:40 PM

Author(s): Miro Erkintalo, Goery Genty, Tampere Univ. of Technology (Finland); Benjamin Wetzel, John M. Dudley, Univ. de Franche-Comté (France)
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The propagation of short pulses in optical fibers is commonly modeled by the generalized Nonlinear Schrödinger equation which includes the frequency-dependence of the dispersion and nonlinear response and the Raman response of silica. It is also common to model the Raman response based on the assumption of a material response that varies linearly with frequency. Here, we examine in detail the accuracy and limitations of this widely used approach. Our major conclusion is that the linear Raman gain approximation performs very poorly in parameter regimes typical of many experimental studies, introducing for example significant errors and artifacts into the spectral and statistical properties of supercontinuum spectra.

The need for speed: 100 Gb/s and its utility beyond fiber efficiency

Paper 7960-19 of Conference 7960
Date: Wednesday, 26 January 2011
Time: 3:30 PM – 4:00 PM

Author(s): Reg Wilcox, Huawei Technologies Co., Ltd. (China)
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In fiber optic transmission system, network economics have traditionally driven the deployment of technologies enabling higher per wavelength transmission speeds. For bit rates up to 10 Gb/s the decision point for a system upgrade was governed by the transponder cost break point of four times the bandwidth for 2.5 times the cost. Starting with 40 Gb/s systems, other factors started to influence deployment decisions. With 100 Gb/s starting to become commercially available, there are indications that the economics over 40 Gb/s systems will be much improved. However, other factors will again be the driving force for installation of this new transmission rate. These include fiber bandwidth efficiency, latency, packet switching efficiency and operational costs. This presentation will explore these factors including the economics to outline a service provider's motivation to install 100 Gb/s line systems.

Laser beam projection with adaptive fiber array systems

Paper 7914-47 of Conference 7914
Date: Wednesday, 26 January 2011
Time: 4:00 PM – 4:30 PM

Author(s): Mikhail A. Vorontsov, Thomas Weyrauch, Univ. of Dayton (United States); Leonid A. Beresnev, Gary W. Carhart, U.S. Army Research Lab. (United States); Svetlana L. Lachinova, Ling Liu, Univ. of Maryland, College Park (United States); Jiang Liu, U.S. Army Research Lab. (United States)
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Coherent combining of ultrashort fiber-amplified laser pulses

Paper 7914-48 of Conference 7914
Date: Wednesday, 26 January 2011
Time: 4:30 PM – 4:50 PM

Author(s): Enrico Seise, Arno Klenke, Jens Limpert, Andreas Tünnermann, Friedrich-Schiller-Univ. Jena (Germany)
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We present a new peak-power scaling concept based on the coherent addition of amplified ultrashort laser pulses. We realized different interferometer setups with active stabilization where two channels were combined with a polarization-dependent beam splitter. The stabilization was done by measuring the polarization state after the combination with a Hänsch-Couillaud-detector and driving a piezo-stage to adjust the optical path length of one interferometer arm. With a laser system using a mode-locked laser source it was possible to coherently combine fiber-amplified ultrashort laser pulses with a combining efficiency of more than 95% and a pulse width significantly below 1ps.



Characterization of 2D surface imaging of tissue optical properties using a submillimeter fiber optic probe

Paper 7896-78 of Conference 7896
Date: Wednesday, 26 January 2011
Time: 4:40 PM – 5:00 PM

Author(s): Vikrant Sharma, Hanli Liu, The Univ. of Texas at Arlington (United States)
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Broad-band light reflectance spectroscopy (LRS) of tissue with sub-millimeter fiber optic probes in the visible and near-infrared range has been used for differentiation of tissue types in various applications. In this paper, we demonstrate the 2D imaging capability of single fiber-optic probe, by scanning a surface area. Tissue-simulating phantoms were constructed by mixing blood with intralipid as the surrounding medium and having blood-contained glass capillaries embedded in the medium. Maps of hemoglobin derivatives and scattering coefficient were obtained. Lateral resolution and penetration depth were characterized for a bifurcated probe with 100µm source and detector fiber diameters, and 100µm source-detector separation.

Emission behavior of active optical silica fiber with doped polymer cladding layer

Paper 7935-41 of Conference 7935
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Hiroyuki Mochizuki, Kensuke Murai, National Institute of Advanced Industrial Science and Technology (Japan)
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Active optical fibers have attracted much attention as key devices of information communication technologies. We fabricated an active optical fiber consisting of a silica core and a polymer cladding layer dispersed with an organic orange-red laser dye. This active optical fiber emitted doughnut-shaped luminescence from its silica core when pumped by an incident beam at 488 nm of a pulsed laser into the silica core. The doughnut-shaped luminescence was attributed to the laser dye even in the cladding layer because its emission color was orange-red and no emission was observed from a non-doped optical fiber by the same pumping. The doughnut-shaped luminescence was not observed by pumping the lateral aspect of the optical fiber. Pumping on the cladding layer did not allow us to observe the doughnut-shaped luminescence. The doughnut-shaped luminescence was found to be amplified spontaneous emission (ASE,) and its spectra of the ASE became narrower with pumping energy.

Fiber-coupled superconducting nanowire single photon detector for quantum key distribution

Paper 7960-28 of Conference 7960
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Labao Zhang, Zhao-Qing Yuan, Lin Kang, Jian Chen, Peiheng Wu, Chunhai Cao, Nanjing Univ. (China)
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In this paper, the fabrication details and optimization of micro-fabrication process were presented for developing superconducting nanowire single-photon detectors (SNSPD). Besides, the devices failure analysis was also introduced. With those methods, we successfully fabricated high-quality SNSPDs whose maximum system efficiencies were up to 30% for 660 nm wavelength and 4.2% for 1550 nm wavelength according to the single-photon detection experiment. At the dark count rate of 10 c/s, the detection efficiencies were 20% (660 nm) and 3% (1550 nm) with the SNSPD fabricated with above mentioned methods.

Spectroscopic properties of Nd Er codoped glasses for solar-pumped fiber lasers

Paper 7934-48 of Conference 7934
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Shintaro Mizuno, Toyota Central Research and Development Labs., Inc. (Japan); Hiroyuki Kawai, Hiroyuki Nasu, Mark A. Hughes, Takenobu Suzuki, Toyota Technological Institute (Japan); Kazuo Hasegawa, Hiroshi Ito, Toyota Central Research and Development Labs., Inc. (Japan); Yasutake Ohishi, Toyota Technological Institute (Japan)
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In this study, the absorption and fluorescence characteristics of Nd,Er-codoped fluoride glasses were investigated under simulated sunlight or laser beam illumination to show their solar energy application potential. Er was assumed to enable the energy transfer in Nd-doped fluoride glasses to enhance their NIR emission due to additional light absorption in the ultraviolet and visible regions. The energy transfer from Er to Nd was studied by 404nm laser light illumination which is absorbed by Er3+ ions only. Strong contribution of Er absorption to 1.05 um emission was observed in Nd,Er-codoped fluoride glasses proposing them for use in solar energy applications.

Coherent and spectral beam combining of fiber lasers

Paper 7914-49 of Conference 7914
Date: Thursday, 27 January 2011
Time: 8:20 AM – 8:50 AM

Author(s): Steven J. Augst, MIT Lincoln Lab. (United States)
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Yb-fiber lasers for frequency comb spectroscopy: from XUV to mid-IR

Paper 7917-44 of Conference 7917
Date: Thursday, 27 January 2011
Time: 8:50 AM – 9:20 AM

Author(s): Ingmar Hartl, Axel Ruehl, Martin E. Fermann, IMRA America, Inc. (United States); Arman Cingoz, JILA-AMO (United States) and National Institute of Standards and Technology (United States); Dylan C. Yost, JILA-AMO (United States); Florian Adler, Jun Ye, JILA-AMO (United States) and National Institute of Standards and Technology (United States)
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The introduction of Yb-fiber technology to frequency combs has led to dramatic performance improvements in relative comb tooth linewidth to the sub-mHz level [1], fiber-laser comb spacing to the GHz level [2], and comb average powers to the 80W level [3]. The latter facilitates coherent, nonlinear frequency conversion to the difficult-to-access mid-infrared and XUV spectral regions. They are important for emerging comb spectroscopy applications in the molecular fingerprint region, for example for the monitoring of atmospheric trace gases or chemical reaction dynamics, and in the XUV region for spectroscopic tests of fundamental physical theories.

Mitigation of thermal lensing effect as a brightness limitation of fiber coupled laser diodes

Paper 7953-49 of Conference 7953
Date: Thursday, 27 January 2011
Time: 10:30 AM – 10:50 AM

Author(s): John G. Bai, Paul O. Leisher, Chendong Bai, Louis J. Bintz, David C. Dawson, Ling Bao, Jun Wang, Mark A. DeVito, Robert J. Martinsen, Jim Haden, nLIGHT Corp. (United States)
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High brightness applications limit the power rating of 9xx nm single emitters to ~10W, due to a rapid increase in the slow-axis divergence, and hence reduction in beam quality, with drive current. In this work, we show that thermal lensing in the slow axis is the predominant cause of beam quality degradation and report on recent efforts to mitigate the effect by directly engineering the thermal path of the emitter. It is expected that approaches such as these are critical to enabling continued power enhancements for high-brightness fiber coupled laser diodes.

Design of a fiber-coupled superconducting nanowire detector array system for the LLCD

Paper 7923-17 of Conference 7923
Date: Thursday, 27 January 2011
Time: 10:50 AM – 11:10 AM

Author(s): Matthew E. Grein, MIT Lincoln Lab. (United States)
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Design of a fiber-coupled superconducting nanowire detector array system for the LLCD.

Sub-micron texturing of silicon wafer with fiber laser

Paper 7926-6 of Conference 7926
Date: Thursday, 27 January 2011
Time: 11:10 AM – 11:30 AM

Author(s): Hamid Farrokhi, Wei Zhou, Nanyang Technological Univ. (Singapore); Hongyu Zheng, Zhongli Li, A*STAR Singapore Institute of Manufacturing Technology (Singapore)
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Laser texturing is extensively investigated for modifying surface properties. A continuous wave (CW) fiber laser (λ= 1090nm) was used to pattern a silicon wafer surface in ambient and O2 atmosphere respectively. The O2 gas stream was delivered through a coaxial nozzle to the laser spot. Characterization of the patterned features was carried out by surface profiling, scanning electron microscope (SEM), Energy dispersive X-ray spectroscopy (EDS or EDX) and Raman spectroscopy. Formation of laser-induced SiO2 sub-micron bumps was observed, which were analyzed and shown to cause changes in surface wetability and reflectivity.

Hybrid large mode area photonic crystal fiber for distributed spectral filtering and single-mode operation

Paper 7914-61 of Conference 7914
Date: Thursday, 27 January 2011
Time: 2:40 PM – 3:00 PM

Author(s): Federica Poli, Enrico Coscelli, Univ. degli Studi di Parma (Italy); Thomas T. Alkeskjold, NKT Photonics A/S (Denmark); Davide Passaro, Annamaria Cucinotta, Stefano Selleri, Univ. degli Studi di Parma (Italy); Lasse Leick, Jes Broeng, NKT Photonics A/S (Denmark)
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The properties of a large mode area Yb-doped double-cladding hybrid PCF, with antisymmetric high-index inclusions, have been analyzed. Simulations, carried out through a finite-element based modal solver, and experimental measurements have demonstrated the narrow spectral filtering capability of this PCF, both when straight and coiled, with a passband of about 80 nm in the Yb gain region. Moreover, high-order mode suppression has been demonstrated with a proper air-hole size or with the core down-doping. Finally, stress-induced birefringence due to the Ge-rods has been investigated, accounting for the polarization-maintaining behaviour of the manufactured fiber.

New developments in high-power fiber lasers based on alternative materials

Paper 7914-66 of Conference 7914
Date: Thursday, 27 January 2011
Time: 5:00 PM – 5:20 PM

Author(s): Andreas Langner, Mario Such, Gerhard Schötz, Heraeus Quarzglas GmbH & Co. KG (Germany); Stephan Grimm, Florian Just, Martin Leich, Christian Mühlig, Jens Kobelke, Anka Schwuchow, IPHT Jena (Germany); Oliver Mehl, Olaf Strauch, Björn Wedel, HIGHYAG Lasertechnologie GmbH (Germany); Georg Rehmann, Volker K. Krause, Laserline GmbH (Germany)
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Sintering of Yb-doped silica granulates is well established to produce homogeneous Yb-doped silica rods. By the new developed modified laser induced deflection (LID) we pre-characterized the pure material absorption and compared these with fiber attenuation. Filament and stacking techniques enable the preparation of complex and precise fiber structures. Ultra large active core fibers have been produced by surrounding Yb-doped silica rods with silica and/or special doped rods and tubes (e.g., Fluorine). The laser fibers have been tested in high power fiber laser setups. We present the laser performance tests, where we achieved output powers >1 kW with excellent long term laser stability.

Structural analysis of articular cartilage using multiphoton microscopy: input for biomechanical modelling

Paper 7903-119 of Conference 7903
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Magnus B. Lilledahl, Norwegian Univ. of Science and Technology (Norway); David M. Pierce, Gerhard Holzapfel, Technische Univ. Graz (Austria); Catharina de Lange Davies, Univ. of Duissburg-Essen (Germany)
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Cartilage diseases in articular joints is a growing medical problem in the industrialized world, as the population becomes older and the incidence of obesity increases. Biomechanical modeling of cartilage is a valuable tool in the management of cartilage pathologies. We have developed a method for the quantitative characterization of articular cartilage using Fourier image analysis techniques on multiphoton images. Specifically, the primary direction and degree of dispersion of the collagen fibers has been quantified. These parameters can be used directly in a novel constitutive model describing the biomechanical properties of cartilage. As a proof of concept study, we imaged articular cartilage from the knee of chicken, sectioned in three orthogonal planes, to quantify the direction and dispersion of the collagen fibers in three dimensions througout the cartilage volume. A better description of the collagen fibers, yielding a higher fidelity biomechanical model will increase our understanding of the biomechanics of cartilage which will open up new opportunities for improving clinical management of cartilage diseases.

Single emitter based diode lasers with high brightness and narrow linewidth

Paper 7918-21 of Conference 7918
Date: Monday, 24 January 2011
Time: 9:50 AM – 10:10 AM

Author(s): Stefan W. Heinemann, Boris Regaard, Torsten Schmidt, Benjamin Lewis, Fraunhofer USA, Inc. (United States)
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High brightness, narrow linewidth fiber coupled diode lasers based on multiple single emitters rely on four core technologies, a precision reflow process, a customized automated alignment station for high yield production of single emitter based high brightness diode lasers, wavelength stabilization with external grating and efficient optical stacking achieving 85% optical fill factors. Results on ultra high brightness fiber coupled diode laser are presented with 700W out of a 200um/0.22NA fiber and 2nm linewidth over the whole output power range.

Course: Applied Nonlinear Frequency Conversion

Date: Monday, 24 January 2011
Time: 8:30 AM – 5:30 PM

Instructor(s): Ruediger Paschotta, RP Photonics Consulting GmbH (Switzerland)
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This course provides detailed knowledge on the operation and design of nonlinear frequency conversion devices. The emphasis is on frequency conversion in (2) nonlinear crystals, such as frequency doubling, sum and difference frequency generation and parametric oscillation. In addition, Raman amplifiers and lasers (including bulk and fiber-based devices) are treated, and briefly also Brillouin fiber lasers. The course gives an overview of nonlinear crystal materials and addresses the details of phase matching, showing how a certain phase-matching configuration may be chosen based on given device requirements. For various cases, it is shown how to estimate the achievable conversion efficiency. The conversion of short and ultrashort optical pulses is also discussed. Some case studies demonstrate the influence of various practical issues.

Active cooling fiber delivery device for bovine prostate vaporization with high-power 180W 532-nm laser

Paper 7883B-49 of Conference 7883B
Date: Saturday, 22 January 2011
Time: 2:00 PM – 2:20 PM

Author(s): Steven Peng, Hyun Wook Kang, Homa Pirzadeh, Douglas G. Stinson, American Medical Systems, Inc. (United States)
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Second-harmonic generation and multiphoton microscopy for automatic texture analysis of human of elastic fibers and collagen distribution in human thoracic aorta

Paper 7903-9 of Conference 7903
Date: Sunday, 23 January 2011
Time: 11:50 AM – 12:05 PM

Author(s): Gislaine Vieira, Vitor B. Pelegati, André A. Thomaz, Daniela Peixoto Ferro, Randall L. Adam, Carlos Lenz Cesar, Konradin Metze, Univ. Estadual de Campinas (Brazil)
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Automated assembly processes for high power single emitter diode lasers

Paper 7918-17 of Conference 7918
Date: Sunday, 23 January 2011
Time: 4:50 PM – 5:10 PM

Author(s): Jörg Pierer, Markus Lützelschwab, Sylvain Grossmann, Christian A. Bosshard, Ctr. Suisse d'Electronique et de Microtechnique SA (Switzerland); Bernd Valk, Reinhard Brunner, Rainer K. Bättig, Norbert Lichtenstein, Oclaro, Inc. (Switzerland)
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Modules consisting of multiple single emitters pose demanding challenges on assembly and production capabilities. A fiber coupled module has been designed with the objective to achieve 100 W optical power from a 105 µm, NA 0.15 fiber. The module consists of 2 times 6 vertically stacked single emitters combined by polarization multiplexing. Special attention was paid to the development of a very robust low cost pigtail. The developed semiautomatic highly accurate process enables assembly times way faster than possible in a purely manual procedure. The achievable yield in combination with low material costs indicates an excellent potential for the realization of cost efficient laser modules.

Bright laser source with high power single mode emitting diode laser stacked array assembly and fiber coupling

Paper 7918-25 of Conference 7918
Date: Monday, 24 January 2011
Time: 11:40 AM – 12:00 PM

Author(s): Martin Forrer, FISBA OPTIK AG (Switzerland); Christian A. Bosshard, Ctr. Suisse d'Electronique et de Microtechnique SA (Switzerland); Norbert Lichtenstein, Oclaro, Inc. (Switzerland)
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High power single mode emitting diode laser arrays (SEAL) with optimized electrical and geometrical parameters have been developed capable to deliver more than 40 W emission power per bar. Based on this platform an expandable prototype solution is presented for fiber coupling of a stacked array of SEAL with more than 100 W to an optical fiber with diameter of 100 micron and NA of 0.22. Advanced methods of controlled assembly of micro-optics by laser-soldering have been used therefore. The development and integration are focused on a compact and scalable concept with scalability in internal and external factors.

Hybrid photonic integrated circuits for faster and greener optical communication networks

Paper 7941-11 of Conference 7941
Date: Monday, 24 January 2011
Time: 2:00 PM – 2:30 PM

Author(s): Leontios Stampoulidis, Efstratios Kehayas, CONSTELEX Technology Enablers (Greece); Lars Zimmermann, IHP GmbH (Germany) and Technische Univ. Berlin (Germany)
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We present current development efforts on hybrid photonic integration for new generation "faster and greener" Tb/s-capacity optical networks. On the physical layer, we present the development of a robust and versatile, silicon-based photonic integration platform that acts as a technology "blender" bringing together different material systems including InP, GaAs and SiGe. On the application layer we present optical transport and routing systems integrated on the hybrid photonic platform; 100GbE transceiver PICs and Tb/s-capacity wavelength routers can now be implemented using passive silicon interferometers and hybridly integrated III-V optical amplifiers, modulators and detectors.

Ultra rapid dispersion measurement of optical fibers and optical assemblies at 1310 nm and 1550 nm

Paper 7914-16 of Conference 7914
Date: Monday, 24 January 2011
Time: 3:50 PM – 4:10 PM

Author(s): Wolfgang Wieser, Benjamin R. Biedermann, Thomas Klein, Christoph M. Eigenwillig, Robert A. Huber, Ludwig-Maximilians-Univ. München (Germany)
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We present a novel method to measure the dispersion of km-long fibers and through optical components. The technique is based on a rapidly swept Fourier domain mode locked (FDML) laser driven at 50kHz repetition rate. Amplitude modulation with 400MHz and phase analysis yield the time-of-flight values over a continuous wavelength tuning range. Setups covering both common telecom wavelengths ranges (130nm around 1550nm and 110nm around 1310nm) are demonstrated. The high acquisition speed of 10µs for individual wavelength-resolved traces enables real-time monitoring with update rates >100Hz even when averaging several hundred acquisitions for improved accuracy.

Development of a micromirror-scanned multimodal CARS miniaturized microscope for the in-vivo study of spinal cord disorders

Paper 7903-45 of Conference 7903
Date: Monday, 24 January 2011
Time: 3:53 PM – 4:05 PM

Author(s): Sangeeta Murugkar, Brett Smith, Majid Naji, Univ. of Ottawa (Canada); Craig Brideau, Peter Stys, Univ. of Calgary (Canada); Hanan Anis, Univ. of Ottawa (Canada)
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We discuss the design and implementation of a novel micromirror-scanned multimodal coherent anti-Stokes Raman scattering (CARS) miniaturized microscope probe for imaging of injured and recovering spinal cords in a single living animal over time. The miniaturized microscope design includes fiber based delivery, biaxial scanning using a microelectromechanical system (MEMS) mirror and custom miniaturized optics corrected for chromatic aberration at the pump and Stokes wavelengths for CARS. The basic design concept, major engineering challenges, solutions, and some preliminary results are presented. We demonstrate CARS and two photon excitation fluorescence microscopy in a benchtop setup with the miniaturized optics and MEMS scanning.

Amplification of ps-pulses from freely triggerable gain-switched laser diodes at 1062 nm and second harmonic generation in periodically poled lithium niobate

Paper 7917-6 of Conference 7917
Date: Tuesday, 25 January 2011
Time: 8:20 AM – 8:40 AM

Author(s): Thomas Schönau, Sina M. Riecke, Kristian Lauritsen, Rainer Erdmann, PicoQuant GmbH (Germany)
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We present a compact frequency-doubled laser source with fundamental wavelength operation at 1062 nm. A freely triggerable seed diode laser delivers sub-100 ps pulses, in the Picojoule range, up to 80 MHz repetition rate. After amplification in a Ytterbium-doped fiber amplifier, the average power exceeds 300 mW at 40 MHz, which corresponds to 10 nJ pulses and about 100 W of peak power. The output beam is then focussed into periodically poled lithium niobate for second harmonic generation (SHG). Conversion efficiency and beam characteristics of the second harmonic are measured for different crystal lengths and compared to theoretical models.

Design and implementation of an optical contact sensor to automate in-vivo data acquisition upon mucosa contact with a fiber optic light scattering probe

Paper 7891-19 of Conference 7891
Date: Tuesday, 25 January 2011
Time: 9:40 AM – 10:00 AM

Author(s): Sarah Ruderman, Northwestern Univ. (United States); Scott Mueller, American BioOptics (United States); Jeremy D. Rogers, Vadim Backman, Northwestern Univ. (United States)
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Contact fiber-optic probes are useful in noninvasive applications and real-time analysis of tissue properties. Interactions between these probes and tissue surface can introduce variability due to length of contact time between probe and tissue. Automating measurements in a reliable manner can mitigate temporal variability. Utilizing fiber-optic probes previously designed by our group, we developed an optical method to automatically trigger acquisition upon tissue contact. Analysis of previous data determined the wavelength range where changes in reflected intensity indicate tissue proximity and contact. Initial in vivo studies assess reliability and timing of contact detection, reduction in variability, and probe-user techniques.

Subsurface temperature imaging techniques during infrared laser-tissue interactions

Paper 7897-32 of Conference 7897
Date: Tuesday, 25 January 2011
Time: 1:30 PM – 1:50 PM

Author(s): Rudolf M. Verdaasdonk, Vrije Univ. Medical Ctr. (Netherlands); Stefan Been, John H. Klaessens, Univ. Medical Ctr. Utrecht (Netherlands)
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A new strategy has been developed obtain thermal images below the surface of biological tissue by viewing through a ZincSelenide window to study and obtain a better understanding of the thermo dynamics during laser-tissue interaction of various IR lasers and delivery systems. In addition, high speed color Schlieren imaging was applied to visualize temperature gradients in a transparent tissue model. The thermal, high speed and normal imaging techniques showed to be both compatible and complementary. The subsurface thermal imaging enable comparison and better understanding of the tissue effects between various continuous wave and pulsed IR laser systems and delivery systems.

Piezo-electric transducer-based miniature catheter for ultra-high-speed endoscopic optical coherence tomography

Paper 7889-44 of Conference 7889
Date: Tuesday, 25 January 2011
Time: 2:15 PM – 2:30 PM

Author(s): Tsung-Han Tsai, Massachusetts Institute of Technology (United States); Benjamin M. Potsaid, Massachusetts Institute of Technology (United States) and Thorlabs Inc. (United States); Martin F. Kraus, Massachusetts Institute of Technology (United States) and Friedrich-Alexander-Univ. Erlangen-Nürnberg (Germany); Jonathan J. Liu, Chao Zhou, Massachusetts Institute of Technology (United States); Joachim Hornegger, Friedrich-Alexander-Univ. Erlangen-Nürnberg (Germany); James G. Fujimoto, Massachusetts Institute of Technology (United States)
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We developed a piezoelectric transducer (PZT) based miniature catheter with an outer diameter of 3mm for ultrahigh speed endoscopic optical coherence tomography (OCT) using Fourier domain modelocked (FDML) laser at a 240kHz axial scan rate. The miniaturized PZT bender actuates a fiber to provide high scanning speed. The side-viewing probe can be pulled back for a long distance to acquire three-dimensional dataset covering a large area on the specimen. Operating with a high speed data acquisition system, OCT imaging with 4mm imaging range, 9.6um axial resolution, 20um lateral resolution, and frame rate of 480 frames per second (fps) is demonstrated.


Optimum signal constellations for high-speed optical metro networks and beyond

Paper 7959-3 of Conference 7959
Date: Tuesday, 25 January 2011
Time: 4:20 PM – 4:40 PM

Author(s): Jianyong Zhang, Beijing Jiaotong Univ. (China); Ivan B. Djordjevic, The Univ. of Arizona (United States)
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In order achieve beyond 400 Gb/s serial optical transmission using commercially available equipment, we propose the use of channel capacity achieving modulation formats. We propose the method to determine the optimum signal constellation for an arbitrary dispersion map. This method consists of the following key steps: (i) estimate the information rate by the forward-step of BJCR algorithm, (ii) use the constrained stochastic Arimoto-Blahut algorithm to determine the optimum input distribution, and (iii) determine the optimum signal constellation by minimizing the mean-square error of optimum source. We will study different dispersion maps currently in use and for each of them we will determine the optimum signal constellation. It will be shown that with the optimum signal constellation for the dispersion map composed of periodically deployed SMF and DCF sections we can achieve the spectral efficiency of 6 bits/s/Hz per single polarization for metro and medium-haul applications.

Optimum signal constellations for high-speed optical metro networks and beyond

Paper 7960-3 of Conference 7960
Date: Tuesday, 25 January 2011
Time: 4:20 PM – 4:40 PM

Author(s): Jianyong Zhang, Beijing Jiaotong Univ. (China); Ivan B. Djordjevic, The Univ. of Arizona (United States)
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In order achieve beyond 400 Gb/s serial optical transmission using commercially available equipment, we propose the use of channel capacity achieving modulation formats. We propose the method to determine the optimum signal constellation for an arbitrary dispersion map. This method consists of the following key steps: (i) estimate the information rate by the forward-step of BJCR algorithm, (ii) use the constrained stochastic Arimoto-Blahut algorithm to determine the optimum input distribution, and (iii) determine the optimum signal constellation by minimizing the mean-square error of optimum source. We will study different dispersion maps currently in use and for each of them we will determine the optimum signal constellation. It will be shown that with the optimum signal constellation for the dispersion map composed of periodically deployed SMF and DCF sections we can achieve the spectral efficiency of 6 bits/s/Hz per single polarization for metro and medium-haul applications.

Three-dimensional finite element modeling of liquid crystal devices

Paper 7955-9 of Conference 7955
Date: Tuesday, 25 January 2011
Time: 4:30 PM – 5:00 PM

Author(s): Pieter J. M. Vanbrabant, Jeroen Beeckman, Kristiaan Neyts, Univ. Gent (Belgium); Richard W. James, Eero Willman, F. Anibal Fernandez, Univ. College London (United Kingdom)
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A finite element framework is presented to combine advanced three-dimensional liquid crystal director calculations with a full-vector beam propagation or waveguide mode analysis. This approach becomes especially valuable to analyze and design structures in which disclinations or diffraction effects play an important role. The wide applicability of the approach is illustrated in our overview by examples ranging from small pixel LCOS microdisplays and spatial light modulators for beam steering to tunable liquid crystal waveguides, couplers and photonic crystal fibers. Evaluation versions of the beam propagation method and modesolver algorithms are available at www.elis.ugent.be/ELISgroups/lcd/research/research.php.

Sub-10 picosecond pulses from a fiber-amplified and optically compressed passively Q-switched microchip laser

Paper 7914-37 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 4:40 PM – 5:00 PM

Author(s): Alexander Steinmetz, Dirk Nodop, Andreas Martin, Jens Limpert, Andreas Tünnermann, Friedrich-Schiller-Univ. Jena (Germany)
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We present an experimentally confirmed approach based on nonlinear optical compression of passively Q-switched pulses accessing sub-10 ps domain, which is so far dominated by mode-locked systems. The concept implements the SPM-induced spectral-broadening of passively Q-switched microchip pulses in optical waveguides and a supplementary compression with bulk optics e.g. a pair of diffraction gratings or a chirped-bragg-grating. The initial 150 ps seed-pulses are fiber-amplified and spectrally broadened to 0.53 nm. Using a conventional 1740 l/mm diffraction-grating based pulse-compressor, the pulses are compressed to a duration of smaller than 6.5 ps assuming a numerically calculated de-convolution factor of 0.735.

Sub-10 picosecond pulses from a fiber-amplified and optically compressed passively Q-switched microchip laser

Paper 7912-37 of Conference 7912
Date: Tuesday, 25 January 2011
Time: 4:40 PM – 5:00 PM

Author(s): Alexander Steinmetz, Dirk Nodop, Andreas Martin, Jens Limpert, Andreas Tünnermann, Friedrich-Schiller-Univ. Jena (Germany)
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We present an experimentally confirmed approach based on nonlinear optical compression of passively Q-switched pulses accessing sub-10 ps domain, which is so far dominated by mode-locked systems. The concept implements the SPM-induced spectral-broadening of passively Q-switched microchip pulses in optical waveguides and a supplementary compression with bulk optics e.g. a pair of diffraction gratings or a chirped-bragg-grating. The initial 150 ps seed-pulses are fiber-amplified and spectrally broadened to 0.53 nm. Using a conventional 1740 l/mm diffraction-grating based pulse-compressor, the pulses are compressed to a duration of smaller than 6.5 ps assuming a numerically calculated de-convolution factor of 0.735.

2nd and 3rd harmonic generation from a fiber-amplified 100-ps, high-repetition rate and single-frequency passively Q-switched microchip laser

Paper 7914-39 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 5:40 PM – 6:00 PM

Author(s): Alexander Steinmetz, Dirk Nodop, Friedrich-Schiller-Univ. Jena (Germany); Georg Sommerer, Alexander Wissel, Stefan Spiekermann, Ingo Freitag, InnoLight GmbH (Germany); Jens Limpert, Andreas Tünnermann, Friedrich-Schiller-Univ. Jena (Germany)
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We demonstrate a pulsed laser source with 23.7 watts at 532 nm and 9.5 watts at 355 nm by frequency conversion of a fiber-amplified, single-frequency and passively Q-Switched microchip laser providing 100-ps, 1 MHz pulses. The second harmonic generation is realized with a non-critically phase-matched, 20 mm long LBO crystal resulting in a conversion efficiency of 62.6 %. For the third harmonic generation, a subsequent sum frequency generator is placed in a small distance after the SHG-stage into collimated beam and is based on a 7 mm long, critically phase-matched LBO crystal resulting in IR-to-UV conversion efficiency of >23.8 %.

2nd and 3rd harmonic generation from a fiber-amplified 100-ps, high-repetition rate and single-frequency passively Q-switched microchip laser

Paper 7912-39 of Conference 7912
Date: Tuesday, 25 January 2011
Time: 5:40 PM – 6:00 PM

Author(s): Alexander Steinmetz, Dirk Nodop, Friedrich-Schiller-Univ. Jena (Germany); Georg Sommerer, Alexander Wissel, Stefan Spiekermann, Ingo Freitag, InnoLight GmbH (Germany); Jens Limpert, Andreas Tünnermann, Friedrich-Schiller-Univ. Jena (Germany)
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We demonstrate a pulsed laser source with 23.7 watts at 532 nm and 9.5 watts at 355 nm by frequency conversion of a fiber-amplified, single-frequency and passively Q-Switched microchip laser providing 100-ps, 1 MHz pulses. The second harmonic generation is realized with a non-critically phase-matched, 20 mm long LBO crystal resulting in a conversion efficiency of 62.6 %. For the third harmonic generation, a subsequent sum frequency generator is placed in a small distance after the SHG-stage into collimated beam and is based on a 7 mm long, critically phase-matched LBO crystal resulting in IR-to-UV conversion efficiency of >23.8 %.

Stimulated Raman scattering mitigation through amplified spontaneous emission simultaneous seeding on high-power double-clad fiber pulse amplifiers

Paper 7914-96 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Miguel Melo, João M. Sousa, Martin O. Berendt, Multiwave Photonics (Portugal)
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The evolution of stimulated Raman scattering (SRS) with simultaneous seeding of amplified spontaneous emission (ASE) and signal pulse on forward high power Ytterbium-doped double-clad fiber amplifier is studied. It is experimentally demonstrated that increasing the ASE seeded power the energy contained in the first-order Stokes Raman pulse can be significantly reduced. The seeded ASE changes the gain dynamics of the high power amplifier stage, reducing SRS and enabling higher extracted energy from the signal pulse. The signal and Raman spectral components are discriminated and the temporal evolution of each component for different input ASE power levels is analyzed individually.

Synchronized dual wavelength programmable laser with 75nm wavelength difference tuning

Paper 7914-99 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Bryan Buorgoyne, Youngjae Kim, Alain Villeneuve, Genia Photonics Inc. (Canada)
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Today, most tuneable fiber-based lasers generating dual wavelengths yield identical spacing between the wavelengths while tuning. Having variable spacing between the wavelengths would give way to a tuneable THz source, up to 10 THz, through difference frequency generation. We present here such a source which is a programmable laser based on an actively mode-locked dispersion-tuned picosecond fiber laser delivering two wavelengths in the C and L bands respectively. The difference between these wavelengths is rapidly adjustable over a 75 nm band while the laser is tuning. Laser pulses are as short as 30 ps.

In-vitro Raman spectroscopic process monitoring of tissue engineered oral mucosa constructs

Paper 7897-45 of Conference 7897
Date: Wednesday, 26 January 2011
Time: 9:10 AM – 9:30 AM

Author(s): Arindam Ganguly, Jacqueline H. Cole, Shiuhyang Kuo, Cynthia L. Marcelo, Univ. of Michigan (United States); Kenji Izumi, Niigata Univ. (Japan); Stephen E. Feinberg, Michael D. Morris, Univ. of Michigan (United States)
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We will describe the use of Raman spectroscopy for in vitro process analysis of tissue engineered oral mucosa constructs. The objectives are to investigate noninvasive Raman spectroscopy as a possible in-line process monitoring technique for oral mucosa tissue engineering and to identify and derive metrics for normal vs. abnormal tissue development which will provide process control variables. The engineered tissue is a human oral mucosa, called Ex Vivo Produced Oral Mucosal Equivalent (EVPOME), and has been previously used successfully in clinical trials for intraoral grafting. We will discuss the conditions needed for successful use of non-confocal optics in this highly turbid system.

Versatile 1 W narrow band 976 nm light source

Paper 7953-35 of Conference 7953
Date: Wednesday, 26 January 2011
Time: 11:40 AM – 12:00 PM

Author(s): Stefan Mohrdiek, Hans-Ulrich Pfeiffer, Evgeny A. Zibik, Boris N. Sverdlov, Norbert Lichtenstein, Tomas Pliska, Oclaro, Inc. (Switzerland)
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We report on development of novel curved waveguide (CWG) laser devices, where the emission wavelength centered at ~976 nm is stabilized to a 20 dB bandwidth of less than 100 picometer by using fiber Bragg gratings (FBG). The devices, assembled in telecom type housings, provide up to 1 W of low-noise and kink-free CW power. In addition pulse operation in nanosecond range is also investigated. The spectral stabilization time to the wavelength of the FBG is limited by the external cavity roundtrip of ~2 ns. The achieved side mode suppression ratio is well below - 50 dB.

Nonlinear strong and weak pulse generation for the B92 protocol

Paper 7948-28 of Conference 7948
Date: Wednesday, 26 January 2011
Time: 1:45 PM – 2:05 PM

Author(s): Anil Prabhakar, S. Thiruthakka Thevan, Indian Institute of Technology Madras (India)
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We use four-wave mixing and self-gated single photon detection to implement the B92 protocol. An active mode-locked Er-doped fiber ring laser acts as pump in the FWM experiment. A continuous wave DFB laser acts as the idler. Both pump and idler are amplified through a gain-saturated EDFA before being fed into highly nonlinear fiber. At the receiver, the strong (pump) and weak (FWM) pulses are wavelength demultiplexed and the former triggers the detection of the latter. We have observed a QBER of less than 10% when using this scheme.

The use of the nonlinear optical loop mirror for investigations of pulse breakup in optical fibers

Paper 7917-33 of Conference 7917
Date: Wednesday, 26 January 2011
Time: 2:30 PM – 3:00 PM

Author(s): Evgeny A. Kuzin, Baldemar Ibarra-Escamilla, Instituto Nacional de Astrofísica, Óptica y Electrónica (Mexico); Olivier Pottiez, Ctr. de Investigaciones en Óptica, A.C. (Mexico)
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For long pump pulses supercontinuum starts from pulse breakup resulting to formation of a bunch of solitons. The process is investigated mostly by measuring of a spectrum at the fiber output. The extraction of individual solitons or groups of solitons with similar parameters from the bunch can reveal details that are hidden when only an output spectrum is measured. We demonstrate theoretically and experimentally that the NOLM is a viable device allowing the extraction of individual solitons, groups of solitons with similar parameters, and also the measurement of the power distribution of solitons resulting from pulse breakup.

Development of broadband optical frequency resource over 8.4-THz in 1.0-μm waveband for photonic transport systems

Paper 7958-14 of Conference 7958
Date: Wednesday, 26 January 2011
Time: 5:10 PM – 5:30 PM

Author(s): Naokatsu Yamamoto, National Institute of Information and Communications Technology (Japan); Yu Omigawa, Yuta Kinoshita, Aoyama Gakuin Univ. (Japan); Atsushi Kannno, Kouichi Akahane, Tetsuya Kawanishi, National Institute of Information and Communications Technology (Japan); Hideyuki Sotobayashi, Aoyama Gakuin Univ. (Japan)
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For an enhancing usable optical frequency resources in a future photonic network system, we have recently focused on a use of a novel wavelength band such as a 1-μm waveband (Thousand-band: T-band) together with the conventional C- and L-bands. In this study, we develop broadband potentialities in the T-band. An error-free 10-Gbps photonic transmission over a few-km long holey-fiber is successfully demonstrated for the wavelength range of 1037-1068-nm, which corresponds to the optical frequency range of 8.4-THz. Pioneering a broadband optical frequency resources is positively applied for a wavelength-division-multiplex network in the T-band.

Qualitative analysis of ultra-short optical dissipative solitary pulses in the actively mode-locked semiconductor heterolaser with an external fiber cavity

Paper 7933-74 of Conference 7933
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Alexandre S. Shcherbakov, Instituto Nacional de Astrofísica, Óptica y Electrónica (Mexico); Joaquin Campos Acosta, Consejo Superior de Investigaciones Científicas (Spain); Pedro Moreno Zarate, Instituto Nacional de Astrofísica, Óptica y Electrónica (Mexico); Alicia Pons Aglio, Consejo Superior de Investigaciones Científicas (Spain)
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Broadband ubiquitous femto-cell network with MIMO distributed antenna system over WDM-PON

Paper 7958-16 of Conference 7958
Date: Thursday, 27 January 2011
Time: 10:50 AM – 11:20 AM

Author(s): Katsumi Iwatsuki, Takayoshi Tashiro, Kazutaka Hara, Tomohiro Taniguchi, Jun-Ichi Kani, Naoto Yoshimoto, NTT Corp. (Japan); Kenji Miyamoto, Tatsuya Nishiumi, Takeshi Higashino, Katsutoshi Tsukamoto, Shozo Komaki, Osaka Univ. (Japan)
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This talk introduces a research on a convergence of WDM access and femto-cell MIMO antenna system which can provides next generation wireless accesses. We discuss distribution of MIMO antenna, method of RoF-MIMO signals over WDM-PON, and configurations of center station and remote base stations, and then propose a novel network architecture for Giga-bit throughput in broadband ubiquitous networks converged WDM access and femto-cell MIMO antenna system.

Record-high output power from large area photonic crystal band-edge lasers

Paper 7942-17 of Conference 7942
Date: Thursday, 27 January 2011
Time: 1:30 PM – 1:50 PM

Author(s): Sunghwan Kim, Sungmo Ahn, Jeongkug Lee, Heonsu Jeon, Seoul National Univ. (Korea, Republic of); Christian Seassal, Ecole Centrale de Lyon (France)
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We demonstrate high power laser operation of a large area surface-emitting photonic crystal (PC) band-edge laser (BEL). We employed a Γ-point band-edge mode for the surface-emitting property. In order to generate a square-lattice PC structure on large area and at high throughput, we applied laser-holographic lithography to an InAsP/InP epilayer bonded onto a fused silica substrate. Direct butt-end multimode fiber coupling (for simultaneous and efficient optical pumping of the BEL and collecting the BEL output from a large area) enabled us to achieve a fiber-coupled output of ~2.6 mW, which is the record-high output from any kind of PC lasers.

Diode laser for endodontic treatment: investigations of light distribution and disinfection efficiency

Paper 7884-1 of Conference 7884
Date: Sunday, 23 January 2011
Time: 8:00 AM – 8:20 AM

Author(s): Karl Stock, Rainer Graser, Martin Udart, Alwin Kienle, Raimund Hibst, Univ. Ulm (Germany)
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To find out whether high power NIR laser bacterial killing is caused by a photochemical or a photothermal process we heated bacteria suspensions of E. coli by a water bath and by a diode laser. Furthermore, bacteria suspensions were irradiated while the temperature was fixed by ice water. In order to optimize the irradiation of the root canal, we designed special fiber tips with radial light emission characteristic by optical ray tracing simulations. Furthermore we irradiated human teeth using different fiber tip geometries and measured the resulted light and heat distribution. Comparison of killing rates between laser and water based heating shows no significant differences. Irradiation of root canals using fiber tips with radial light emission results in minor irradiation of the apex and higher temperature increase on root canal surface.

ACP-OPLL photonic integrated circuit for high dynamic range RF/photonic links

Paper 7936-15 of Conference 7936
Date: Sunday, 23 January 2011
Time: 2:30 PM – 2:50 PM

Author(s): Yifei Li, Univ. of Massachusetts Dartmouth (United States); Ashish Bhardwaj, John E. Bowers, Univ. of California, Santa Barbara (United States); Peter R. Herczfeld, Drexel Univ. (United States)
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Fiber-optic links are attractive for transmitting microwave/millimeter wave signals for radar, imaging, astronomy, and many other analog communication systems. However, the current fiber-optic links suffer from a limited spurious free dynamic range (SFDR). For solution, a new coherent fiber-optic link using linear phase modulation/demodulation has been proposed. The new link should be able to achieve an SFDR two orders higher. The key for this link is an OPLL linear phase demodulator. Due to the stringent delay requirement, the OPLL can only be realized by a novel attenuation-counter-propagating (ACP) device design and by photonic integration. In this paper we describe the design, fabrication and measurement of the generation ACP-OPLL photonic integrated circuits.

A time-domain fluorescence diffusion optical tomography system for breast tumor diagnosis

Paper 7896-101 of Conference 7896
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Wei Zhang, Feng Gao, Xin Wang, Jiao Li, Fang Yang, Zhongxing Zhou, Limin Zhang, Huijuan Zhao, Tianjin Univ. (China)
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A prototype time-domain fluorescence diffusion optical tomography (FDOT) system using near-infrared light is presented. The system employs two pulsed light sources, 32 source fibers and 32 detection channels, working separately for acquiring the temporal distribution of the photon flux on the tissue surface. The light sources are provided by low power picosecond diode lasers at wavelengths of 785 nm and 830 nm, and a 32×1-fiber-optic-switch sequentially directs light sources to the object surface through 32 source fibers. The light signals re-emitted from the object are collected by 32 detection fibers connected to eight 4×1-fiber-optic-switches and then routed to 4 time-resolved measuring channels, each of which consist of a collimator, a filter wheel, a photomultiplier tube (PMT) and a time-correlated single photon counting (TCSPC) module. The performance and efficiency of the designed system are assessed by reconstructing the fluorescent- and optical-images of a solid phantom.

Nonlinear miniaturized microscope with spectral detection for in-vivo tissue imaging

Paper 7903-114 of Conference 7903
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Johan van Voskuilen, Jerfey van Weelden, Oleg Nadiarnykh, Utrecht Univ. (Netherlands); Giju Thomas, Henricus J. C. M. Sterenborg, Erasmus MC (Netherlands); Hans C. Gerritsen, Utrecht Univ. (Netherlands)
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A nonlinear miniaturized microscope is presented designed for nonlinear optical biopsies, which uses resonant scanning. The scanner is fiber coupled to the microscope using a double clad photonic crystal fiber. This facilitates signal guiding of single-mode infrared excitation and broadband multimode visible emission. Group velocity dispersion by the fiber is pre-compensated with a grating pair. Emission is detected using a custom built spectrograph with a sensitive EMCCD. The nonlinear excitation provides contrast without applying stains in living tissue. Signals are detected from, amongst others, auto-fluorescence of NADH, FAD, melanin, and SHG of collagen. Tests and results on tissue are shown.

Continuous-wave optical stimulation of the rat prostate nerves using an all-single-mode 1455 nm diode laser and fiber system

Paper 7883G-162 of Conference 7883G
Date: Monday, 24 January 2011
Time: 1:30 PM – 1:50 PM

Author(s): Serhat Tozburun, The Univ. of North Carolina at Charlotte (United States); Gwen A. Lagoda, Arthur L. Burnett M.D., The Johns Hopkins Univ. (United States); Nathaniel M. Fried, The Univ. of North Carolina at Charlotte (United States)
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Continuous-wave, near-infrared laser radiation delivered through 200-m-core multimode optical fibers was used during previous studies for optical nerve stimulation (ONS) of rat prostate nerves. This study describes an all-single-mode laser/fiber ONS system as an alternative to multimode laser/fiber delivery. Successful ONS was observed at temperatures of 42 oC using 30 mW of power from a 1455 nm diode laser. ICP signal-to-noise-ratios up to 4:1, and minimum ICP response times of 3 s were recorded. Continuous-wave optical stimulation of rat prostate nerves is feasible using an all-single-mode laser/fiber ONS system. Advantages include reduced cost and size and improved spatial beam profile.

The use of Monte Carlo simulations to determine the spatial distribution of sensitivity of Raman fiber probes

Paper 7891-10 of Conference 7891
Date: Monday, 24 January 2011
Time: 2:40 PM – 3:00 PM

Author(s): Ingo Gersonde, Laser- und Medizin-Technologie GmbH, Berlin (Germany); Carina Reble, Technische Univ. Berlin (Germany) and Laser- und Medizin-Technologie GmbH, Berlin (Germany); Gerd Illing, Laser- und Medizin-Technologie GmbH, Berlin (Germany)
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Raman spectroscopy is a powerful analytic tool to discriminate tissue compositions. For the interpretation of the measurement results information about the sampling volume is required, especially in inhomogeneous tissue. Since biological tissues are optically turbid, the sampling volume is determined by both the tissue optical properties and the measurement geometry. With our Monte-Carlo method we determine a weight function, which defines the spatial distribution of sensitivity of the Raman measurement. This is then used to calculate the influence of absorption and reduced scattering coefficients on the sampling volume of different fiber configurations. Furthermore, the influence of the measurement geometry characterized by different fiber diameters and the overlap or spatial offset of excitation and detection fiber is compared.

100W high-brightness multi emitter laser pump

Paper 7918-30 of Conference 7918
Date: Monday, 24 January 2011
Time: 3:00 PM – 3:20 PM

Author(s): Richard Duesterberg, Lei Xu, Jay A. Skidmore, James Guo, Jane Cheng, Jihua Du, Brad Johnson, David L. Vecht, Nicolas Guerin, Benlih Huang, Peter Cheng, Reddy Raju, Kong Weng Lee, Jason Cai, Victor V. Rossin, Erik P. Zucker, JDSU (United States)
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We report results of a spatially-multiplexed broad area laser diode platform designed for efficient pumping of fiber lasers or direct-diode systems. Optical output power in excess of 100W from a 105um core, 0.15NA fiber is demonstrated with high coupling efficiency. The compact form factor and low thermal resistance enable tight packing densities needed for kW-class fiber laser systems. Broad area lasers have been optimized for maximum coupling / wall plug efficiencies for this design. In addition to performance characteristics, an update on long term reliability testing of 9XXnm broad area laser diodes will also be provided.

Determining the optical properties in a fibrous turbid medium

Paper 7897-25 of Conference 7897
Date: Tuesday, 25 January 2011
Time: 9:10 AM – 9:30 AM

Author(s): Ali S. Shuaib, Gang Yao, Univ. of Missouri-Columbia (United States)
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We investigated the possibility of retrieving optical properties in anisotropic tissue using time-resolved measurements. An isotropic diffuse model was used to determine the optical properties from simulated time-resolved reflectance. The derived reduced scattering coefficient (μ's) was close to the background μ's value when the measurement position was parallel with the fiber. The derived μ's was different from that of the cylinder and background when measured at 90 degree to the fiber orientation. If the fiber size is known, the μ's associated with the cylinders can be derived by using a correction coefficient.



Quantitative analysis of diseased horse tendons using Fourier-transform-second-harmonic generation imaging

Paper 7903-17 of Conference 7903
Date: Sunday, 23 January 2011
Time: 2:55 PM – 3:10 PM

Author(s): Sivaguru Mayandi, Sushmitha Durgam, Raghu Ambekar Ramachandra Rao, David Luedtke, Glenn A. Fried, Allison Stewart, Kimani C. Toussaint, Jr., Univ. of Illinois at Urbana-Champaign (United States)
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Fourier transform-second-harmonic generation imaging is used as the quantitative technique to assess the structure of collagen fibers in tendonitis-induced horse tendons. Fiber orientation, isotropy, and the ratio of forward to backward SHG signal (F/B ratio) are calculated for normal and diseased horse tendons. Results show that the normal tendon possesses minimal isotropic regions and small standard deviations in the histograms of orientation and F/B ratio, indicating a regular fiber organization. However, diseased horse tendons exhibit a higher number of isotropic regions, and larger standard deviations of the measured parameters, suggesting significantly disorganized collagen fibers.

CMOS photonic crystal and slow light

Paper 7943-10 of Conference 7943
Date: Sunday, 23 January 2011
Time: 3:30 PM – 4:00 PM

Author(s): Toshihiko Baba, Yokohama National Univ. (Japan)
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This presentation focuses CMOS photonic crystals (PCs) and slow light devices. CMOS technology allows the integration of spotsize converters (SSC), heaters, and PIN structures. The technical difficulty in integrating air-bridge PCs and SSCs can be overcome by multi-step masking and etching. SSCs reduce fiber-to-fiber loss to <10 dB. Heaters are used as tuning/trimming elements. Low heating efficiency in air-bridge PCs will be improved by optimizing heat flow and/or silica-clad devices. PIN structures are used as phase shifters in modulators. Low-dispersion slow light enhance the phase shift. They can also be used as fast dynamic tuning element in slow light devices.

Non-confocal detection in spectrally encoded endoscopy

Paper 7893-19 of Conference 7893
Date: Sunday, 23 January 2011
Time: 4:40 PM – 5:00 PM

Author(s): DongKyun Kang, Milen S. Shishkov, Brett E. Bouma, Guillermo J. Tearney, Massachusetts General Hospital (United States)
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Spectrally encoded endoscopy (SEE) is a miniature endoscopy technology that encoded one transverse coordinate of the specimen in the wavelength. Here, we present a new method of conducting SEE that provides speckle-free images with a high signal-to-background ratio. The new method utilizes a small-core fiber assembled coaxially with a GRIN lens for illumination and a large-core fiber integrated to the side of the GRIN lens for detection. Images of a human finger were obtained in vivo by the new method, and unprocessed images showed clear evidence of the detailed structure of fingerprints without any noticeable speckle noises.

An algorithm for the correction of 2D near-infrared fluorescent signal using 3D intravascular ultrasound pullback information

Paper 7892-31 of Conference 7892
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Georgios Mallas, Massachusetts General Hospital (United States) and Northeastern Univ. (United States); Dana H. Brooks, Northeastern Univ. (United States); Amir Rosenthal, Massachusetts General Hospital (United States) and Helmholtz Zentrum München GmbH (Germany); Claudio Vinegoni, Marcella A. Calfon, Massachusetts General Hospital (United States); R. Nika Razansky, Technische Univ. München (Germany); Farouc A. Jaffer M.D., Massachusetts General Hospital (United States); Vasilis Ntziachristos, Helmholtz Zentrum München GmbH (Germany)
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We have developed a Near Infrared Fluorescence (NIRF) fiber optic catheter and have displayed its ability in vivo to image atherosclerotic plaques, using appropriate NIR fluorescent probes. The system returns true 2D images and operates in conjunction with a coaxial Intravascular Ultrasound (IVUS) device. IVUS data yield 3D images of the internal structure of a vessel and are used in our system for anatomical guidance. Using the IVUS images we are building an accurate hybrid fluorescence-IVUS data inversion scheme that takes into account photon propagation in the vessel to correct for the non-linear dependence of light intensity obtained on the distance of the fluorescence region from the fiber tip, leading to quantitative imaging. The effectiveness of the algorithm is displayed through appropriate phantom experimental results.

K-domain linearization of wavelength swept laser for optical coherence tomography

Paper 7894-35 of Conference 7894
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Byoung Chang Lee, Chungnam National Univ. (Korea, Republic of); Tae-Joong Eom, Gwangju Institute of Science and Technology (Korea, Republic of); Min Yong Jeon, Chungnam National Univ. (Korea, Republic of)
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We propose a new method for k-domain linearization based on fiber Bragg gratings (FBGs) in a wavelength swept source for optical coherence tomography (OCT). The wavelength swept source with a scanning fiber Fabry-Perot tunable filter is constructed on the basis of the conventional ring laser cavity. The five FBGs are used to recalibrate the nonlinear response from the wavelength swept source. We achieve a good quality sample imaging using the k-domain linearization algorithm based on FBGs. The sensitivity at 2 mm is improved more than 10 dB after k-domain linearization.

Brightness and power scaling of diode-based light sources

Paper 7918-22 of Conference 7918
Date: Monday, 24 January 2011
Time: 10:10 AM – 10:30 AM

Author(s): Eckard Deichsel, Peter Heist, Lars Wagner, Ekkehard A. Werner, JENOPTIK Laser GmbH (Germany)
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Power and brightness of diode-based light-sources attract more and more attention. High-power and high-brightness diode laser systems address a wide range of applications in the field of direct material processing and pump sources for solid state and fiber lasers. Jenoptik's single-emitter based high-brightness light source offers powers up to 75W with beam-parameter products in the range of 7,5mm*mrad. Based on such modules as base units in a modular building block system, we highlight strategies for power and brightness scaling. Different approaches such as fiber and free-space combining are investigated in detail. Powers in the several 100W to kW class range are demonstrated with remarkable brightness.

Spectrum engineering in whispering gallery mode resonators

Paper 7913-25 of Conference 7913
Date: Monday, 24 January 2011
Time: 10:30 AM – 10:50 AM

Author(s): Andrey B. Matsko, Anatoliy A. Savchenkov, Vladimir S. Ilchenko, David J. Seidel, Lute Maleki, OEwaves, Inc. (United States)
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We show that modification of the shape of the WGM resonator surface results in modification of its spectrum. Two extremes of such a modification are the white light and single mode WGM resonators. The morphology of the resonator structure is used to select the propagating modes in the same manner as the core and cladding in an optical fiber determine the propagation of the mode in an optical fiber. We discuss how to fabricate resonators with several spectral patterns and consider two viable approaches. One is based on the fabrication of the resonator from a preform being a part of an ideal sphere. The other approach is based on the building the resonator out of an ideal cylindrical preform.

Thin glass based packaging and photonic single-mode waveguide integration by ion-exchange technology on board and module level

Paper 7944-11 of Conference 7944
Date: Monday, 24 January 2011
Time: 2:20 PM – 2:40 PM

Author(s): Lars Brusberg, Henning Schröder, Fraunhofer-Institut für Zuverlässigkeit und Mikrointegration (Germany)
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The field of photonic integrated circuits is rapidly growing with strong potential for intra and interchip optical interconnects in data and telecom applications. The O/E integration into the chip and the applied single-mode waveguide structures characterize high integration (small feature size) and high bandwidth density (wavelength multiplexing). Beside ultra-short reach interconnects long-haul single-mode glass fibers build the global telecom network since two decades. A hybrid packaging platform providing 3D optical single-mode links bridge the gap between novel photonic integrated circuits and the glass fibers. We introduce our 3D photonic packaging approach based on thin glass substrates with planar integrated optical single-mode waveguides for optical fiber-to-chip and chip-to-chip links.

Pluggable compact optical connector for Si-photonics chip using MT-ferrule

Paper 7943-24 of Conference 7943
Date: Monday, 24 January 2011
Time: 2:30 PM – 2:50 PM

Author(s): Do-Won Kim, Jun Yeong Lee, Jonghun Kim, Gyungock Kim, Electronics and Telecommunications Research Institute (Korea, Republic of)
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A cost-effective and compact pluggable optical connector for optical coupling between the single mode fiber and the silicon grating coupler has been fabricated using a MT-Ferrule. It can reduce the cost down to 1/30. Since it has a compact dimension of 6.4 mm x 2.45 mm x 1.5 mm and guide holes for passive plugging for the external light source, it can be directly bonded to the Si-photonics chip, accomplishing increased degree of freedom in designing of optical modules. The optical insertion loss of the connector showed constant values of ~1.80 dB for the wavelength range from 1520 nm to 1620 nm. The UV-curable epoxy adhesive used for bonding enhanced the coupling efficiency between fiber and grating coupler. The coupling loss of the connector was 4.7 dB.

Development of a combined ultrasound and photo-acoustic endoscopic probe

Paper 7893-43 of Conference 7893
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Wei Wei, Univ. of California, Irvine (United States); Xiang Li, Qifa Zhou, K. Kirk Shung, The Univ. of Southern California (United States); Zhongping Chen, Univ. of California, Irvine (United States)
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A miniaturized imaging probe combining ultrasound and photoacoustic endoscopy has been developed. The free space pulse laser beam was coupled into and delivered by a multimode fiber. A ring shape ultrasound transducer was fabricated to receive pulse echo ultrasound and photoacoustic signals as well. The light-guiding optical fiber, the ring ultrasound transducer and a mirror-based reflection media for both the laser beam and ultrasound signal were integrated into the probe with a final packaged diameter of 2.6 mm. The performance of the probe was tested from imaging a graphite rod. The imaging ability of this dual-modality system was demonstrated by imaging the cross section of a rabbit aorta.

Estimation of chromophore concentrations with diffuse optical spectroscopy in the near-infrared wavelength range up to 1600 nm

Paper 7907-44 of Conference 7907
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Rami Nachabe, Benno H. W. Hendriks, Martin B. van der Mark, Marjolein van der Voort, Adrien E. Desjardins, Philips Research Nederland B.V. (Netherlands); Henricus J. C. M. Sterenborg, Erasmus MC (Netherlands)
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Diffuse optical spectra were acquired on phantoms and animal tissues in the near infrared wavelength range up to 1600 nm by using a two-fiber optical probe with a fiber distance separation of 2.5 mm. The spectra were analyzed by a fit-model derived from diffusion theory. In this fit-model, measured absorption coefficients of pure water and lipid are used to estimate the concentration of these chromophores in phantoms and animal tissues. The results show that the lipid concentration in the phantoms, with different values of the reduced scattering coefficient, can be determined within 5% accuracy.

Photoacoustic endoscopy using polymer microring resonators

Paper 7899-102 of Conference 7899
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Sung-Liang Chen, Tao Ling, Hyoung Won Baac, L. Jay Guo, Univ. of Michigan (United States)
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Photoacoustic (PA) imaging has potential for a variety of medical studies. We have developed a miniaturized imaging probe for PA endoscopy application. The probe consists of a light-guiding optical fiber, a polymer microring resonator as an ultrasonic sensor, and a prism to guide ultrasonic waves. To evaluate the performance of the PA probe, we performed a linear B-scan image of a black-dye-loaded polystyrene bead. The results show a high SNR and a high axial resolution at pulsed laser fluence under ANSI safety limit. A fiber-based wideband photoacoustic source can be integrated in the future to provide ultrasound imaging capability.

Multi-THz fields exceeding 100 MV/cm: an ultrabroadband source for sub-cycle nonlinear optics

Paper 7917-11 of Conference 7917
Date: Tuesday, 25 January 2011
Time: 10:30 AM – 11:00 AM

Author(s): Alexander Sell, Friederike Junginger, Olaf Schubert, Bernhard Mayer, Univ. Konstanz (Germany); Tobias Kampfrath, Martin Wolf, Fritz-Haber-Institut der Max-Planck-Gesellschaft (Germany); Daniele Brida, Marco Marangoni, Giulio Cerullo, Politecnico di Milano (Italy); Alfred Leitenstorfer, Rupert Huber, Univ. Konstanz (Germany)
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We present a table-top source of extremely intense multi-THz transients covering the spectral regime between 0.1 and 140 THz. Electric field amplitudes of up to 108 MV/cm and pulse durations as short as a single cycle are demonstrated with our hybrid Er:fiber-Ti:sapphire laser system. All THz waveforms are electro-optically detected. The multi-branch fiber laser generates gate pulses as short as 4.3 fs. Our high-field THz facility opens the door to extremely nonlinear optics in a previously hard-to-access spectral regime. First applications include THz coherent control and four-wave mixing studies as well as all-magnetic control of coherent spin waves.

Spectroscopic swept-source optical coherence tomography for hemoglobin saturation level detection

Paper 7890-40 of Conference 7890
Date: Tuesday, 25 January 2011
Time: 2:45 PM – 3:00 PM

Author(s): Jae Du Cho, Hyung Seok Lee, Myung-Yong Jeong, Chang-Seok Kim, Pusan National Univ. (Korea, Republic of); Hyun-Woo Song, Bong Kyu Kim, Electronics and Telecommunications Research Institute (Korea, Republic of)
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Spectroscopic optical coherence tomography (OCT) is a recently developed technical extension of OCT for functional images. Conventional spectroscopic OCT's have used a line scan camera with broadband light source centered at 800 nm, however, they suffered several limitations, such as limited pixel number of camera, non-Gaussian shape of light spectra, low sensitivity and high cost. In this work, we present a spectroscopic swept-source based on an 800 nm optical semiconductor amplifier gain for hemoglobin saturation level detection and functional imaging. Bandwidth of wavelength swept laser is measured around 40 nm centered at 800nm and instantaneous linewidth is also measured around 0.1 nm. By using of this novel swept-source, we can achieve a higher sensitivity image due to balanced detector and simpler design of all-fiber spectroscopic OCT system. For a simple design of optical system, we employed all-fiber ring cavity swept source and modified Michelson interferometer.

Filterless swept-source based on dispersion tuning for high-speed optical coherence tomography

Paper 7889-53 of Conference 7889
Date: Tuesday, 25 January 2011
Time: 5:00 PM – 5:15 PM

Author(s): Changho Chong, Kouki Totsuka, Takuya Suzuki, Keiji Isamoto, Santec Corp. (Japan); Yuya Takubo, Shinji Yamashita, The Univ. of Tokyo (Japan)
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We proposed a swept source optical coherence tomography system based on dispersion tuning technique. Dispersion tuning is realized by wavelength-tunable mode-locked fiber laser using highly dispersive element in the extended cavity structure. The laser is configured in a ring cavity with a wideband semiconductor optical amplifier (SOA) at 1.3 μm and mode locking is achieved by direct modulation of the injection current to the SOA, and a dispersion compensation fiber (DCF) is used as intracavity dispersion. Structure with tunable-filterless design provides significantly robust and reliable solution in terms of non-mechanical tuning. The sweep over wide wavelength range can be achieved at up to 300 kHz. The modulation signal itself can be used as external clocking when digitizing the OCT signal.

Tailoring wavelength sweep for SS-OCT with a programmable picosecond laser

Paper 7889-56 of Conference 7889
Date: Tuesday, 25 January 2011
Time: 5:45 PM – 6:00 PM

Author(s): Guy Lamouche, Sébastien Vergnole, National Research Council Canada (Canada); Youngjae Kim, Bryan Burgoyne, Alain Villeneuve, Genia Photonics Inc. (Canada)
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A unique and novel, fully programmable picosecond laser source that offers complete tailoring of the wavelength sweep that benefits SS-OCT applications is presented. Along with the advantages of a fiber-based architecture, the source is a fully programmable, electronically controlled mode-locked laser capable of rapidly tuning the wavelength and pulse characteristics. As well, several sweep modes and configurations are available which can be by range, with linear sweeps in wavelength or k-space, or by arbitrary wavelengths. The output is delivered through a single mode polarization maintaining fiber. The source design is discussed and its use in SS-OCT is illustrated.

Measurement of the refractive index of liquids in magnetic field using common-path optical coherence tomography

Paper 7942-28 of Conference 7942
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Hae-Dong Yim, El-Hang Lee, Seung-Gol Lee, Se-Geun Park, Beom-Hoan O, Inha Univ. (Korea, Republic of)
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We present a measurement system of liquids refractive index based on a common-path spectral domain optical coherence tomography(OCT). Our measurement system is consisted of the circulator, broadband light source, spectrometer and sensor head. The sensor head is composed of metal mirror, fiber connector and small air gap between the mirror and the fiber end. The reflected spectrum is measured in air and liquids. In air measurement, the IFFT signal of measured spectrum gives only one peak near the mirror by the air gap. On the other hand, in liquid measurement, the mirror peak is shifted to the longer distance by the liquid refractive index. Therefore, we can calculate the refractive index of liquid using the shifted peak distance. We measure the refractive index of some liquids. The refractive index of distilled water and ethanol is 1.3468 and 1.3635 in 1550 nm. The refractive index of some liquids such as methanol, acetone and index matching oil will be discussed in presentation.

Refractometric sensor using poli (p-phenylenevinylene) PPV and poli(p-xylylenes) PPX

Paper 7935-47 of Conference 7935
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Maria E. Armas Alvarado, Daniel Orquiza de Carvalho, Gustavo P. Rehder, Jonas Gruber, Rosamaria W. C. Li, Marco I. Alayo Chavez, Univ. de São Paulo (Brazil)
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In this work we present a study of the optical gas sensing properties of Poli (p-phenylenevinylene) PPV, and poli(p-xylylenes) PPX deposited by spin-coating. These polymers are easy to process and can be obtained from inexpensive materials. Preliminary results showed a variation of the refractive indices of these polymers (approximately 0.1 RIU - Refractive Index Units) in the wavelength of 632.8 nm when they are exposed to ethanol gas with different concentrations. Two different approaches were used to test these materials as gas sensors. The first approach was through conventional fiber sensing with cladding-stripped optical fiber, and the second one was based on integrated optics.

The effects of photobiomodulation on healing of bone defects in Streptozotocin induced-diabetic rats

Paper 7887-15 of Conference 7887
Date: Saturday, 22 January 2011
Time: 3:10 PM – 3:30 PM

Author(s): Maíra D. M. Costa Lino, Fabiola B. Carvalho, Michel Ferreira Morais, José A. Cardoso, Antônio L. Barbosa Pinheiro, Luciana M. Pedreira Ramalho D.D.S., Univ. Federal da Bahia (Brazil)
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The aim of the present investigation was to assess histologically the effect of LPT (780nm) on the repair of surgical defects created in the femur of diabetic and non-diabetic Wistar Albinus rats. The results showed histological evidence of improved amount of collagen fibers at early stages of the bone healing and increased amount of well organized bone trabeculae at the end of the experimental period on irradiated animals, (diabetic and non-diabetic) compared to non irradiated ones. It is concluded that LPT has a positive biomodulative effect on the healing process of bone defects, even when diabetes mellitus was present.

High-speed swept source based on polygon-scanner filter and Fox-Smith cavity

Paper 7889-97 of Conference 7889
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Pinghe Wang, Beckman Laser Institute and Medical Clinic (United States)
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Abstract: We demonstrate a high-speed and wide-range swept laser for optical coherence tomography (OCT) imaging. The repetition rate of the laser which is twice of the speed of the polygon filter which is achieved by using two delay fibers in a Fox-Smith cavity. The performance of the laser is the following: a scanning range of 80nm centered at 1315nm, coherence length of 4mm and the output power is 10mw at a 45kHz sweeping rate.

Rigorous characterization of surface plasmon modes by using the finite element method

Paper 7941-34 of Conference 7941
Date: Wednesday, 26 January 2011
Time: 8:30 AM – 8:50 AM

Author(s): B. M. Azizur Rahman, Huda Tanvir, Anita Quadir, Ken Grattan, The City Univ. (United Kingdom)
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A rigorous full vectorial finite element-based approach has been developed to characterize a wide range of plasmonic devices, both at optical and terahertz frequencies. Results for wave confinement in gold nanowires, air-core guides and defect-core metal coated photonic crystal fibers and gain threshold optimization of quantum cascaded lasers for terahertz (THz) frequencies will be presented.

Coupled surface plasmon resonance sensor with sensitive liquid crystal layer

Paper 7955-23 of Conference 7955
Date: Wednesday, 26 January 2011
Time: 2:50 PM – 3:10 PM

Author(s): Alaeddin S. Abu-Abed, Univ. of Central Oklahoma (United States); Shadi A. Alboon, Yarmouk Univ. (Jordan); Yongbin Lin, Robert G. Lindquist, The Univ. of Alabama in Huntsville (United States)
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This work presents an optical sensor based on the surface plasmon resonance (SPR) phenomenon involved with liquid crystal (LC) sensitive layer. In this effort, the authors have developed an alternative method to track the state of alignment and degree of ordering of the LC film via the SPR with gold nanoparticles array fabricated on optical fibers tip to enhance the SPR-LC sensitivity. This innovation will transduce the presence of the targeted agents, which deforms the LC profile, into a measurable quantity (the spectral position of the maximum loss in the transmission spectra) via tracking the LC deformation.

Course: Principles and Applications of Optical Coherence Tomography

Date: Sunday, 23 January 2011
Time: 1:30 PM – 5:30 PM

Instructor(s): James G. Fujimoto, Massachusetts Institute of Technology (United States)
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Optical coherence tomography (OCT) is a new imaging modality, which is the optical analog of ultrasound. OCT can perform high resolution cross sectional imaging of the internal structure of biological tissues and materials. OCT is promising for biomedical imaging because it functions as a type of optical biopsy, enabling tissue pathology to be imaged in suit and in real time. This technology also has numerous applications in other fields ranging from nondestructive evaluation of materials to optical data storage. This course describes OCT and the integrated disciplines including fiber optics, interferometry, high-speed optical detection, biomedical imaging, in vitro and in vivo studies, and clinical medicine

Course: Precision Laser Micromachining

Date: Wednesday, 26 January 2011
Time: 8:30 AM – 12:30 PM

Instructor(s): Ronald D. Schaeffer, PhotoMachining, Inc. (United States)
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This course is a comprehensive look at laser technology as applied to precision micromachining. A brief background discussion on laser history, technology and definition of important terms will be presented. Then, available laser sources will be compared and contrasted including CO2, excimer, Nd:YAG, fiber and short pulse lasers. IR and UV material/photon interaction, basic optical components and system integration are also crucial to getting good processing results and these will all be examined in detail. Finally, real applications from the medical, microelectronics, aerospace and other fields will be presented. This course has been greatly expanded to include detailed discussions on short pulse lasers (ps and fs) and their applications, both present and future. In addition, two market areas have been significantly updated - Aerospace/Defense and renewable energy, particularly Solar. One of the biggest growth markets in the laser future (and historically!), the growth of renewable energy applications will infuse hundreds of millions of dollars into the laser community as new electricity generating capability is brought on line.

Course: Solid State Laser Technology

Date: Saturday, 22 January 2011
Time: 8:30 AM – 5:30 PM

Instructor(s): Norman Hodgson, Coherent, Inc. (United States)
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This course provides an overview of the design, performance characteristics and the current state of the art of solid state lasers and devices. The course reviews the laser-relevant properties of key solid state materials, and discusses the design principles for flashlamp pumped and diode-pumped solid state lasers in cw, pulsed, Q-switched and modelocked operation. Solid state media emphasized include Nd and Yb-doped crystals but mid-IR materials such as Tm, Ho and Er-doped fluorides and oxides will be addressed as well. The course will cover the fundamental scaling laws for power, energy and beam quality for various geometries of the gain medium (rod, slab, disk, waveguide) and pumping arrangements (side and end-pumped) and provides an overview of the state-of-the art of solid state lasers. This includes a review of the design and performance of fiber lasers/amplifiers and their comparison to bulk solid state lasers. An overview of the state-of the art of optically pumped semiconductor lasers (OPSL) will also be given. Important technical advances (such as diode pump developments) that allowed the technology to mature into diverse industrial and biomedical OEM devices as well as high power and scientific applications will be highlighted along with some remaining design and performance challenges. Topics also include nonlinear frequency conversion techniques, such as harmonic generation, Raman scattering and parametric processes, commonly used in solid state lasers to extend operation to alternative spectral regimes. The course includes an overview of currently available solid state laser products and their industrial and scientific applications.


Femtosecond laser micro/nano patterning of biological materials

Paper 7925-5 of Conference 7925
Date: Sunday, 23 January 2011
Time: 10:50 AM – 11:20 AM

Author(s): Costas P. Grigoropoulos, Hojeong Jeon, Univ. of California, Berkeley (United States); Hirofumi Hidai, Univ. of California, Berkeley (Japan); David J. Hwang, Univ. of California, Berkeley (United States)
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This talk aims at presenting recent work at the Laser Thermal Laboratory on the microscopic and nanoscale laser modification of biological materials using ultrafast laser pulses. We have devised a new method for fabricating high aspect ratio patterns of varying height by using two-photon polymerization process in order to study contact guidance and directed growth of biological cells. Studies using NIH-3T3 and MDCK cells indicate that cell morphology on fiber scaffolds is influenced by the pattern of actin microfilament bundles. Cells experienced different strength of contact guidance depending on the ridge height. Cell morphology and motility was investigated on micronscale anisotropic cross patterns and parallel line patterns having different aspect ratios. A significant effect on cell alignment and directionality of migration was observed. Cell morphology and motility were influenced by the aspect ratio of the cross pattern, the grid size, and the ridge height. Cell contractility was examined microscopically in order to measure contractile forces generated by individual cells on self-standing fiber scaffolds. We have also introduced a method for generating user-defined nanopatterns of cell adhesion ligands by ablating an ultrathin protein adsorption resistant poly(ethylene glycol) brush layer using focused femtosecond laser pulses to expose an underlying adhesive substrate. The ablated regions were modified with peptides designed to engage with specific receptors. We were able to generate nanometer scale regions of cell adhesive peptides, while independently controlling feature size and spacing, hence allowing direct specification of the number and area of focal adhesion patterns. We have also conducted experiments to determine the effect of laser-induced nanoscale laser topography on cell adhesion.

Breast coil for multiplanar MRI/optical spectroscopy in vivo

Paper 7892-3 of Conference 7892
Date: Saturday, 22 January 2011
Time: 8:50 AM – 9:10 AM

Author(s): Michael A. Mastanduno, Shudong Jiang, Brian W. Pogue, Keith D. Paulsen, Dartmouth College (United States)
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Image-guided optical spectroscopy was developed as a non-invasive tool to compliment MR imaging of breast cancer with functional maps of tissue physiology, prior to biopsy. Because the system cannot provide sensitivity to the entire imaging domain, a device to reposition the optical fibers efficiently to focus on suspicious regions while inside the MRI machine was designed and implemented, increasing 3D sensitivity. We present methodology for optical probe optimization for clinical use and compare results from phantom and in-vivo studies with numerical studies. This interface can utilize multi-modal synergy between MR, absorption, and fluorescence imaging for accurate spatial and functional images.

Multiplexed solid-phase nucleic acid hybridization assays using semiconductor quantum dots as donors in fluorescence resonance energy transfer (FRET)

Paper 7909-11 of Conference 7909
Date: Saturday, 22 January 2011
Time: 2:40 PM – 3:10 PM

Author(s): W. Russ Algar, Ulrich J. Krull, Univ. of Toronto Mississauga (Canada)
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The unique optical properties of quantum dots (QDs) in combination with fluorescence resonance energy transfer (FRET) enable multiplexed bioanalyses with a unique set of advantages. This presentation will describe the preparation, spectroscopy, and analytical performance associated with solid-phase nucleic acid hybridization assays that use mixed films of quantum dots and DNA probes immobilized on optical fibers. The simultaneous detection of up to four DNA targets is possible in the ensemble using a single substrate and single excitation source, and without spatial registration, sorting methods, or single molecule spectroscopy. Spectroscopic, engineering, and synthetic strategies for optimization will be highlighted.

The study of proteoglycan concentration on tendons' optical properties by PS-OCT

Paper 7898-7 of Conference 7898
Date: Saturday, 22 January 2011
Time: 3:50 PM – 4:10 PM

Author(s): Ying Yang, Mohammed Ismail, Alan P. Weightman, Ian Wimpenny, Keele Univ. (United Kingdom); Pierre-Olivier Bagnaninchi, The Univ. of Edinburgh (United Kingdom); Mark Ahearne, Keele Univ. (United Kingdom)
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Highly orientated collagen fibers in tendon are known to display birefringent optical properties. Little is known about the influence proteoglycans have on tendons' optical properties. In this study, polarization sensitive optical coherence tomography (PS-OCT) has been used to reveal the relationship between proteoglycan concentration and tendon properties in terms of birefringence. Tendons dissected from freshly slaughtered rats and chicken were scanned by PS-OCT. The proteoglycans were extracted using guanidine HCl. Time lapse PS-OCT images were collected throughout the extraction processing. The birefringence of the tendons decreased systematically regardless of the species or the tendon location.

In-vivo small animal optical imaging enhanced with indocyanine green and saline

Paper 7892-38 of Conference 7892
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Ning Liu, Yuting Lin, Mitchell Hsing, Orhan Nalcioglu, Gultekin Gulsen, Univ. of California, Irvine (United States)
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We present a comparison of the in vivo mice optical images enhanced with ICG and saline separately. The multimodality imaging system used here combines frequency-domain optical techniques and MRI. 16 fibers (8 illuminations and 8 collections) radially arranged to obtain the transverse images of the mice revealing tumor. The acquisition time for one optical image was 16 seconds. Each dynamic measurement lasted for 50 minutes, with bolus injection at 5mins. The pharmacokinetics of ICG and saline at the same tumor location showed comparable signal level, but opposite curvature variation. The reconstructed tomograms showed enhancement at tumor location in both cases.

Lateral Spread of MEMS WDM Technologies

Date: Monday, 24 January 2011
Time: 10:20 AM – 11:10 AM

Author(s):
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Hiroshi Toshiyoshi, Research Ctr. for Advanced Science and Technology (RCAST), The Univ. of Tokyo (Japan)

Abstract: Optical MEMS technologies originally developed for the WDM system have found a wide range of lateral spreading applications. For instance, we have constructed a novel power-over-fiber type OCT endoscope by using two different wavelengths for powering an electrostatic MEMS scanner and for optical probing; this work is on the extension of a MEMS variable optical attenuator. Another example is a Fabry-Perot interferometer for wavelength filtering that has been redirected to a new use of a tunable color pixel developed in a plastic sheet of large area. We will look into the diverging potential of microelectromechanical modulation in optics.

Biography: Hiroshi Toshiyoshi received Ph.D. degree in EE from the University of Tokyo (U-Tokyo) in 1996, after which he joined the Institute of Industrial Science of U-Tokyo as an Assistant Professor. Since 2009, he is a Professor with Research Center for Advanced Science & Technology of U-Tokyo, where he conducts Optical MEMS projects.

Evaluation of graded index glass waveguides for board-level WDM optical chip-to-chip communications

Paper 7944-5 of Conference 7944
Date: Monday, 24 January 2011
Time: 10:30 AM – 11:00 AM

Author(s): Juergen Schrage, C-LAB (Germany) and Siemens AG (Germany); Oliver Stuebbe, C-LAB (Germany) and Univ. Paderborn (Germany); Lars Brusberg, Fraunhofer-Institut für Zuverlässigkeit und Mikrointegration (Germany); Yasin Soenmez, C-LAB (Germany) and Univ. Paderborn (Germany); Henning Schroeder, Fraunhofer-Institut für Zuverlässigkeit und Mikrointegration (Germany); Rolf Schuhmann, Univ. Paderborn (Germany)
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A Proof-of-Concept for a multi-channel WDM board-level optical communications link is under development. This paper is focusing on theoretical and experimental evaluation of thin-glass based graded index optical waveguides with regard to low loss in the 1310nm regime, preserving light polarization and guiding single mode. Results from characterization (material attenuation, refractive index profiles, coupling efficiency between the glass waveguides and fibers) will be reported. Waveguide modes are determined theoretically from the measured refractive index profiles. Towards improvement of the robustness of the coupling efficiency against misalignments, investigations on the use of tapered waveguide structures will be presented too.

MEMS-based laser scanning microscope for endoscopic use

Paper 7893-1 of Conference 7893
Date: Monday, 24 January 2011
Time: 2:00 PM – 2:20 PM

Author(s): Uwe Schelinski, Jens Knobbe, Hans-Georg Dallmann, Mario Foerster, Michael Scholles, Markus Schwarzenberg, Fraunhofer Institute for Photonic Microsystems (Germany)
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A miniaturized MEMS scanning microscope is presented, which enables endoscopic imaging for medical, biological and technical purposes. It consists of an optical head of only 8 mm diameter that is coupled via optical fibers and wires to a distant unit containing optics and electronics for microscope control and data processing. A PC or notebook is completing the system, acting as user interface, image display and storage. The microscope uses a focused flying laser spot allowing a resolution of about 15 µm within the focus plane. This enables new endoscopic applications as in-vivo investigation of cancer-suspicious tissues in medicine.

MEMS-based laser scanning microscope for endoscopic use

Paper 7930-1 of Conference 7930
Date: Monday, 24 January 2011
Time: 2:00 PM – 2:20 PM

Author(s): Uwe Schelinski, Jens Knobbe, Hans-Georg Dallmann, Mario Foerster, Michael Scholles, Markus Schwarzenberg, Fraunhofer Institute for Photonic Microsystems (Germany)
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A miniaturized MEMS scanning microscope is presented, which enables endoscopic imaging for medical, biological and technical purposes. It consists of an optical head of only 8 mm diameter that is coupled via optical fibers and wires to a distant unit containing optics and electronics for microscope control and data processing. A PC or notebook is completing the system, acting as user interface, image display and storage. The microscope uses a focused flying laser spot allowing a resolution of about 15 µm within the focus plane. This enables new endoscopic applications as in-vivo investigation of cancer-suspicious tissues in medicine.

Feasibility of rapid near-infrared diffuse optical tomography by swept-spectral-encoded sequential light delivery

Paper 7896-31 of Conference 7896
Date: Monday, 24 January 2011
Time: 2:10 PM – 2:30 PM

Author(s): Guan Xu, Daqing Piao, Oklahoma State Univ. (United States)
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We investigate the feasibility of rapid near infrared DOT by spectrally-encoded sequential light delivery using wavelength-swept source. The wavelength-swept light beam is dispersed by a spectrometer to form "swept-spectral-encoding" of the light beam which scans linearly across the exit window of the spectrometer and delivers sequential illumination to linearly bundled source fibers. A data acquisition rate of over 1 frame/second is reached from a 4mW swept-source and a 20mm-diameter intra-lumenal applicator with 8 source and 8 detector channels. This new configuration can be readily extended to rapid fluorescence diffuse optical tomography (FDOT) by enabling sequential source-channel-encoded excitations of fluorophores.

A concept for the assembly and alignment of arrayed microelectronic and micro-optical systems for optical multi-gigabit communication

Paper 7944-12 of Conference 7944
Date: Monday, 24 January 2011
Time: 2:40 PM – 3:00 PM

Author(s): Fernando Merchán, Karl-Heinz Brenner, Ruprecht-Karls-Univ. Heidelberg (Germany)
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A concept for the fabrication, assembly and alignment of a multichannel micro optical-coupler and arrayed microelectronic devices placed on a PCB is presented. This concept is based on a micro optical-coupler that integrates several optical sub-systems in a monolithic substrate in order to simplify adjusting processes. The effect of misalignment, tilt, increased roughness or dust on the optical surfaces and possible differences between the optical fibers like irregularities on the end-surfaces are examined with the help of simulations. Bitrates of 120 Gbps in a 12-channel system can be reached using this coupler with commercial electronic devices.

Silicon TSV interposers for photonics and VLSI packaging

Paper 7928-5 of Conference 7928
Date: Monday, 24 January 2011
Time: 4:05 PM – 4:35 PM

Author(s): Nagesh Vodrahalli, ALLVIA, Inc. (United States)
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Abstract Miniaturization, higher performance, and higher bandwidth needs of the electronic industry continue to drive technology innovations through increased levels of integration. Through Silicon Via (TSV) technology along with flip chip technology provides significant improvements over the traditional technologies for packaging VLSI circuits. Silicon Interposers built using TSVs and embedded capacitors SI packaging provide solutions to the next generation needs of VLSI Packaging. TSV Si interposers also provide a paltform for integrating photonic elements like the laser diodes and optical fibers for next generation high bandwidth VLSI packaging. The presentation describes (i) the TSV technologies developed, (ii) implementation of Si TSV interposer with embedded capacitors for VLSI packaging, and (iii) development of Si TSV interposer for integration of photonics and VLSI subsystems. Reliability results of interposers with embedded capacitors are also presented.

1100W Yb:YAG fs INNOSLAB amplifier

Paper 7912-28 of Conference 7912
Date: Tuesday, 25 January 2011
Time: 10:50 AM – 11:20 AM

Author(s): Peter Russbueldt, Fraunhofer-Institut für Lasertechnik (Germany); Torsten G. Mans, RWTH Aachen (Germany); Hans-Dieter Hoffmann, Reinhart Poprawe, Fraunhofer-Institut für Lasertechnik (Germany)
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To transfer femtosecond technology to industrial applications, laser sources of high average power are essential. We demonstrate a compact diode-pumped Yb:KGW femtosecond oscillator - Yb:YAG Innoslab amplifier MOPA with nearly transform and diffraction limited 636 fs pulses at 620 W average output power and 20 MHz repetition rate. By cascading two amplifiers an average output power of 1.1 kW and peak power of 80 MW is achieved in a single, linearly polarized beam. The MOPA is operated at room temperature and no CPA technique is used. The specific properties of Innoslab MOPAs are compared with fibers and thin-disks.

In-vivo, real-time full-field optical coherence tomography of the rat brain

Paper 7889-58 of Conference 7889
Date: Wednesday, 26 January 2011
Time: 8:45 AM – 9:00 AM

Author(s): Jonas R. H. Binding, Ecole Supérieure de Physique et de Chimie Industrielles (France) and Ecole Normale Supérieure (France) and Max-Planck-Institut für medizinische Forschung (Germany); Juliette Ben Arous, Ecole Normale Supérieure (France); Sylvain Gigan, Claude A. Boccara, Ecole Supérieure de Physique et de Chimie Industrielles (France); Jean-François Leger, Laurent Bourdieu, Ecole Normale Supérieure (France)
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Compared to other OCT approaches, full-field OCT has been recognized as a high-resolution method able to provide micron size resolution in 3D on ex vivo samples. Using a fast large full well capacity InAsGa camera we demonstrate the ability of FFOCT to image the brain cortex of living rats. The main features that appear are individual myelin fibers and the blood flow in the vessels where the movements of red blood cells as well as leucocytes can be followed. In addition a precise measurement of the brain refractive index and an estimate of the mean free path have been obtained.

Advances in Lasers and their Impact on Industrial Applications

Date: Wednesday, 26 January 2011
Time: 11:50 AM – 12:30 PM

Author(s):
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Paul E. Denney, Connecticut Ctr. for Advanced Technology, Inc. (USA)

Abstract: Industries have accepted lasers for a number of applications over the past twenty plus years. Laser cutting, drilling, additive manufacturing, marking, scribing/etching, and welding have been accepted as common practices by industries ranging from electronics to automotive. These applications primarily utilized carbon dioxide (CO2) and Nd:YAG lasers which had become "mature".
With development of direct diode, fiber, and disk based laser technologies, the type of lasers for industrial applications are again in flux. These new laser technologies offer economic and technical advantages over the traditional industrial lasers resulting in replacement of older system, expansion in applications for economic or technical reasons, and development of new applications. The presentation will concentrate on how the differences in the new laser technologies are impacting industrial applications and will give some examples.

Biography: Paul Denney is an Application Engineer at Lincoln Electric. He has over 28 years in laser materials processing previously working at the CCAT, EWI, ARL Penn State, Westinghouse Electric R & D Center, and the Naval Research Laboratory. Mr. Denney has his BS and MS in metallurgy from MIT. He is a Fellow Member of LIA and a member of ASM and AWS. He is a co-inventor on 14 laser related patents.

The Future of Photonics: a Forum to Gather Industry Input

Date: Thursday, 27 January 2011
Time: 8:45 AM – 9:30 AM

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Panel Moderators: Eugene Arthurs, CEO, SPIE; Erik Svedberg, Senior Program Officer, National Academies of Science

Come listen and have a say about the input for an analysis of the contribution of optics and photonics and their Grand Challenges of the 21st Century.

This interactive "town hall" session will look at the statement of task and gather input to the committee for a new study of optics and photonics, conducted by the National Academies and its operating arm the National Research Council, with an emphasis on impact. SPIE is supporting an effort to publish an updated version of the 1998 document called Harnessing Light produced by the U.S. National Research Council. This morning session will help harness the community energy to give input to the new study and its committee, which ultimately would inform industry plans and government policy by providing a unique community view of the future directions for our science and technology and market trends. What would make such a study useful to you? Join us in dialogue that drives the collection, analysis, and sharing of information about the future of photonics.

While the original Harnessing Light report has been extremely useful to academic, industrial, and governmental organizations throughout the world, in the past ten years, enormous progress has been made in photonics sciences and technologies. Irrespective of the economic conditions, optical science and engineering is headed toward another strong growth period, driven by developments in advanced materials, solid state lighting, solar technologies, sensors, lasers, imaging, fiber-optic communications, digital photography, diagnostic medicine, computing/processing, and consumer displays/TVs. The impacted markets encompass critical issues that affect society, ranging from energy and healthcare to manufacturing, communications, data storage and security. Therefore the committee will be convened to look at the following issues:
1. Review updates in the state of the science that have taken place since publication of the National Research Council report, Harnessing Light.
2. Identify the technological opportunities that have arisen from recent advances in and potential applications of optical science and engineering.
3. Assess the current state of optical science and engineering in the United States and abroad, including trends in pr

Analysis of tear film thickness by reflectometry technique

Paper 7885-1 of Conference 7885
Date: Saturday, 22 January 2011
Time: 8:15 AM – 8:30 AM

Author(s): Michael R. Wang, Univ. of Miami (United States); Jianhua Wang, Bascom Palmer Eye Institute (United States); Jame J. Yang, New Span Opto-Technology Inc. (United States)
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We report the use of optical reflectometry technique for live eye tear film evaluation. The tear film can be measured by using a white light beam illumination on the eye and with optical fiber coupling to a spectrometer. The non-contact tear film thickness is determined through spectral dependant reflectance evaluation. The measurement is fast and accurate. The tear film measurement can be valuable for dry eye diagnosis and treatment, and for the study of tear film dynamics.

A common-path optical coherence tomography distance sensor-based surface tracking and motion compensation handheld microsurgical tool

Paper 7894-18 of Conference 7894
Date: Saturday, 22 January 2011
Time: 2:40 PM – 3:00 PM

Author(s): Kang Zhang, The Johns Hopkins Univ. (United States); Peter Gehlbach, The Johns Hopkins School of Medicine (United States); Jin Ung Kang, The Johns Hopkins Univ. (United States)
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We have developed a simple and compact hand-held microsurgical tool capable of surface tracking and motion compensation based on common-path optical coherence tomography (CP-OCT) distance-sensor to improve the accuracy and safety of microsurgery. This tool is miniaturized into a 15mm-diameter plastic syringe and capable of surface tracking at less than 5 micrometer resolution and motion compensation at up to 5 Hertz. A phantom made with Intralipid layers is used to simulate a real tissue surface and a single-fiber integrated micro-dissector works as a surgical tip to perform tracking and accurate incision on the phantom surface.

An improved method of laser Thermokeratoplasty to correct presbyopia

Paper 7885-22 of Conference 7885
Date: Saturday, 22 January 2011
Time: 4:30 PM – 4:45 PM

Author(s): Ezra I. Maguen M.D., James J. Salz M.D., Cedars Sinai Medical Ctr. (United States); Michael Berry, NTK Enterprises, Inc. (United States); K. J. Rodgers, Vision Rejuvenation Ctr. (Bahamas); Harry T. Glenn, Advanced Eye Centers, Inc. (United States)
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A new method of epithelium sparing Laser Thermokeratoplasty was clinically evaluated in 37 patients. The laser source is a Thulium fiber laser, 193 µm with a sapphire applanation window.The safety profile was excellent with no adverse events. The uncorrected mean near vision was improved by 4 lines at one day postop regressing to 2 lines at 12 months postop. Uncorrected far vision improved mostly. The procedure could be repeated over time to enhance near vision.

Wavelength stabilized diode laser based devices free of power or efficiency penalties

Paper 7918-12 of Conference 7918
Date: Sunday, 23 January 2011
Time: 2:40 PM – 3:00 PM

Author(s): Keith W. Kennedy, nLIGHT Corp. (United States)
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Utilization of external volume gratings to improve TEM00 power scaling and overall conversion efficiency is rapidly expanding, particularly in pumping the narrow upper laser level of Nd:YAG DPSS lasers at 885 nm and the 1532 nm absorption band of Er:YAG DPSS lasers. It is often believed that the use of such external gratings to wavelength lock diode lasers leads to unavoidable losses in power and efficiency. nLIGHT's vertical integration and unique design methodology has eliminated these problem in our grating-locked diode laser products and will be demonstrated in several wavelength ranges targeting both DPSS as well as fiber laser systems.

Naturally integrated confocal and photoacoustic microscopy

Paper 7899-25 of Conference 7899
Date: Sunday, 23 January 2011
Time: 4:45 PM – 5:00 PM

Author(s): Qing Wei, Univ. of Wisconsin-Milwaukee (United States); Shuliang Jiao, Univ. of Southern California (United States); Hao Feng Zhang, Univ. of Wisconsin-Milwaukee (United States)
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A new imaging device that combines scanning laser confocal microscopy (CM) and optical resolution photoacoustic microscopy (OR-PAM) by using a single-mode fiber optical coupler is developed. Both the optical absorption and back-scattering images of same sample can be acquired simultaneously based on a single light source and these two images are intrinsically registered. The spatial resolutions for both CM and OR-PAM in the combined system were quantified both theoretically and experimentally. The complementary contrast was demonstrated in both phantoms and small animals in vivo.

Reduced speckle, large-area comprehensive imaging by spectrally encoded confocal microscopy

Paper 7893-22 of Conference 7893
Date: Sunday, 23 January 2011
Time: 5:40 PM – 6:00 PM

Author(s): Parama Pal, DongKyun Kang, Brett E. Bouma, Guillermo J. Tearney, Massachusetts General Hospital (United States)
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Spectrally encoded confocal microscopy (SECM) is a reflectance confocal microscopy modality that can image at speeds that range from 10 to 100 times that of video rates and enables comprehensive imaging of luminal organs. We present our design of a probe prototype and associated imaging results. Our prototype consists of an adaptive focusing mechanism that ensures the overlap of the focal plane with the tissue/sample of interest at all times and a dual-clad fiber as the illumination/detection conduit for significantly reducing speckle artifacts in the images.

Suppression of lateral modes in wide aperture laser diodes by digital planar holograms

Paper 7918-24 of Conference 7918
Date: Monday, 24 January 2011
Time: 11:20 AM – 11:40 AM

Author(s): V. Svetikov, Igor Ivonin, A. Koshelev, Nanooptika, LLC (Russian Federation); Leonid V. Velikov, Yu. Vorobiev, Nano-Optic Devices, LLC (United States); Alexander Goltsov, Nanooptika, LLC (Russian Federation); Vladimir V. Yankov, Nano-Optic Devices, LLC (United States)
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High power (HP) laser diodes with apertures around 100um pump solid state and fiber lasers, used for material processing. The necessity for the second stage lasers originates from the well-known limitation of brightness of laser diodes with the aperture increase due to appearance of multiple lateral modes. For the first time we report suppression of lateral modes of 100um wide laser diodes by digital planar holograms. Digital planar hologram narrows spectrum of laser diodes, similar to simple gratings, used in DFB and DBR lasers.

High-power 1.5 micron single-frequency waveguide laser

Paper 7941-8 of Conference 7941
Date: Monday, 24 January 2011
Time: 11:40 AM – 12:00 PM

Author(s): Stefano Taccheo, Swansea Univ. (United Kingdom)
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We report on a 1.5 micron single-frequency waveguide lasers able to provide up to 65 mW output power. The Er:Yb doped 5-cm long active waveguide is made by ion-exchange in phosphate glass. Single-end pumping is provided by a standard 980-nm laser. Pumping efficiency is 32%. Two narrow bandwidth fiber-bragg gratings butt coupled to the waveguide act as laser cavity mirror.

Nonlinear optics in photonic crystal nanocavities: from light sources to quantum photonic interfaces

Paper 7946-10 of Conference 7946
Date: Monday, 24 January 2011
Time: 2:00 PM – 2:30 PM

Author(s): Jelena Vuckovic, Kelley Rivoire, Sonia Buckley, Arka Majumdar, Gary Shambat, Stanford Univ. (United States)
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We have been developing photonic interfaces between infrared and visible wavelength ranges, by employing enhanced nonlinear optical processes in photonic crystal cavities in GaP or GaAs. This is critical for a variety of applications, including building IR detectors on silicon platform, light sources at wavelengths that are difficult to access with existing lasers, and photonic quantum interfaces between the fiber-optic networks and quantum emitters.

Analysis of near-infrared auto-fluorescence peak found in parathyroid and thyroid tissues

Paper 7890-18 of Conference 7890
Date: Monday, 24 January 2011
Time: 3:40 PM – 4:00 PM

Author(s): Constantine Paras, Lisa White, James Broome, Vanderbilt Univ. (United States); Edward M. Brown, Brigham and Women's Hospital (United States); Anita Mahadevan-Jansen, Vanderbilt Univ. (United States)
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Complications such as postoperative hypocalcemia and hypo-parathyroidism can occur due to accidental or incomplete removal of parathyroid glands during endocrine surgery. Initial fiber probe measurements have shown that the parathyroid exhibits markedly higher levels of near-infrared autofluorescence in comparison to all other tissues in the neck. While there are no biological fluorophores reported in the literature expressed by thyroid and parathyroid tissue to explain the documented fluorescence, examination of the anatomy points to several possible candidates. Fluorescence, tissue and protein analysis were performed to assess the likelihood of the different potential fluorophores.

A combined photoacoustic, pulse echo ultrasound and optical coherence tomography endoscopy

Paper 7899-158 of Conference 7899
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Yi Yang, Tianheng Wang, Patrick D. Kumavor, Univ. of Connecticut (United States); Xiang Li, Qifa Zhou, The Univ. of Southern California (United States); Quing Zhu, Univ. of Connecticut (United States)
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We have developed a novel prototype combined photoacoustic, pulse-echo ultrasound and OCT endoscopy. The endoscopy consists of a ball lensed OCT probe, a right-angle multimode fiber for delivering the laser beam for PAT, and a high frequency ultrasound transducer of 35 MHz center frequency. Mouse ear and pig ovary were imaged ex vivo to demonstrate the capability of this new combined endoscopy. Simultaneously acquired microvascular and high resolution anatomy images at subsurface and deeper tissue range demonstrate the synergy of the combined endoscopy over each modality alone.

Transrectal photoacoustic imaging of prostate phantoms using capacitive micromachined ultrasound transducer array

Paper 7899-154 of Conference 7899
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Sri-Rajasekhar Kothapalli, Te-Jen Ma, Srikant Vaithilingam, Erdem Guleyupoglu, Ömer Oralkan, Butrus T. Khuri-Yakub, Sanjiv S. Gambhir, Stanford Univ. (United States)
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To improve the diagnostic accuracy of transrectal ultrasound (TRUS) in prostate cancer screening, we developed a transrectal photoacoustic (TRPA) probe that integrates a fiber optic light guide and capacitive micromachined ultrasound transducer (CMUT) array with a center frequency of 5.5 MHz. 3D volumetric photoacoustic images of prostate phantom show light absorbing objects embedded at different depths (up to 5 cm) inside the phantom. Due to its low noise floor, wide fractional bandwidth, and high sensitivity, the 2-D CMUT array with integrated front-end circuits proves to be an attractive candidate for transrectal photoacoustic volumetric imaging of prostate tissue.

Compact polarization diverse receiver for biomedical imaging applications

Paper 7891-24 of Conference 7891
Date: Tuesday, 25 January 2011
Time: 11:50 AM – 12:10 PM

Author(s): Daniel Neill, Luke Stewart, Finisar Australia (Australia); Huiping Li, Finisar Shanghai, Inc. (China); Tom Killin, Finisar Australia (Australia); Fan Chen, Finisar Shanghai, Inc. (China); Steve Frisken, Glenn Baxter, Simon Poole, Finisar Australia (Australia)
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Advances in biomedical optical technology have often leveraged advances and economies of scale created in the telecommunication space and in particular fiber optic componentry. Recent developments in high speed optical transmission are focusing on coherent detection of phase encoded data and many of the challenges are analogous to those faced in high speed optical imaging based on Swept Frequency Optical Coherence Tomography (SW-OCT). Here we report a novel compact Dual Polarization Quadrature Receiver that has been developed for Telecom applications and present applications including an optical engine for OCT and coherent spectroscopy.

What Er3+-doped laser materials can do for you

Paper 7934-5 of Conference 7934
Date: Tuesday, 25 January 2011
Time: 1:30 PM – 2:00 PM

Author(s): Mark Dubinskii, U.S. Army Research Lab. (United States)
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This presentation provides a brief overview of the very recent and the most promising laser results obtained with Er3+-doped bulk crystalline as well as silica-based fiber laser materials. It indicates that Er3+-ion has a great potential as a dopant for eye-safe lasers in the ~1.6-um wavelength domain as well as in the 3-um wavelength domain if significant power scaling is a goal. Results will be presented and analyzed along with other results of similar importance for laser power scaling.

Phase-locking and synthesis of terahertz quantum cascade laser emission

Paper 7953-26 of Conference 7953
Date: Tuesday, 25 January 2011
Time: 3:30 PM – 4:00 PM

Author(s): Stefano Barbieri, Marco Ravaro, Pierre Gellie, Univ. Paris 7-Denis Diderot (France); Giorgio Santarelli, LNE-SYRTE, CNRS, UPMC (France); Christophe Manquest, Carlo Sirtori, Univ. Paris 7-Denis Diderot (France); Suraj P. Khanna, Edmund H. Linfield, Univ. of Leeds (United Kingdom)
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We demonstrate that the carrier frequency and the repetition rate of a Terahertz (THz) quantum cascade laser (QCL) can be simultaneously phase-locked to the repetition rate of a mode-locked Er-fiber laser. By combining the two stabilization techniques we show that all the longitudinal modes of a multimode QCL emitting at ~2.4THz can be phase-locked, paving the way to the use of these sources for high power, direct THz frequency synthesis.

Multimodal nonlinear optical polarizing microscopy of long-range orientational order in liquid crystals

Paper 7955-10 of Conference 7955
Date: Tuesday, 25 January 2011
Time: 5:00 PM – 5:30 PM

Author(s): Ivan I. Smalyukh, Rahul P. Trivedi, Taewoo Lee, Univ. of Colorado at Boulder (United States)
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We demonstrate orientation-sensitive multimodal nonlinear optical polarizing microscopy capable of probing orientational, polar, and biaxial features of mesomorphic ordering in soft matter systems such as liquid crystals. This technique achieves simultaneous imaging in broadband coherent anti-Stokes Raman scattering, multi-photon excitation fluorescence, and multi-harmonic generation polarizing microscopy modes and is based on the use of a single femtosecond laser and a photonic crystal fiber as sources of the probing light. We demonstrate the viability of this technique for mapping of 3D patterns of molecular orientations and show that images obtained in different microscopy modes are consistent with each other.

Carrier-envelope phase stabilized ~12fs, 0.54mJ, 1.8μm pulses

Paper 7916-37 of Conference 7916
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Chuang Li, Liwei Song, Ding Wang, Canhua Xu, Yuxin Leng, Ruxin Li, Zhizhan Xu, Shanghai Institute of Optics and Fine Mechanics (China)
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We present a three-stage collinear near IR optical parametric amplifier (OPA) with passively stabilized carrier-envelope phase. 1.4mJ/1.8μm/45fs/1kHz pulses are obtained pumped by a 8mJ/800nm/40fs/1kHz non-CEP-stabilized Ti:sapphire laser amplifier. The 1.8μm pulses are then spectrally broadened by nonlinear propagation in an argon-filled hollow-core fiber and subsequently compressed to ~12fs/0.54mJ by use of thin fused silica wedegs with 440 mrad rms CEP fluctuations, making this source suited as a driver for attoscond pulse generation.

Polarization demultiplexing using independent component analysis

Paper 7960-13 of Conference 7960
Date: Wednesday, 26 January 2011
Time: 12:10 PM – 12:30 PM

Author(s): Xiaobo Xie, CREOL, The College of Optics and Photonics, Univ. of Central Florida (United States); Xiang Zhou, AT&T Labs. Research (United States); Guifang Li, CREOL, The College of Optics and Photonics, Univ. of Central Florida (United States)
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Independent component analysis has been applied to polarization demultiplexing for coherent optical fiber communications. Polarization multiplexed QPSK signals were successfully demultiplexed using the tensor based algorithm without any knowledge of the modulation format.

LD pumped high efficiency, high power Tm:YLF laser with adhesive-free bond laser composites

Paper 7912-48 of Conference 7912
Date: Wednesday, 26 January 2011
Time: 2:10 PM – 2:30 PM

Author(s): Xiaodong Mu, Helmuth E. Meissner, Huai-Chuan Lee, Onyx Optics Inc. (United States)
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High efficiency, high power laser operations have been achieved in adhesive-free bonded (AFB) undoped end-capped and segmentally bonded Tm:YLF laser composites. With a fiber coupled 792-nm diode laser as pump source and an end-pump arrangement, 29 W cw output power has been achieved at a wavelength of 1908 nm for a pump power of 65 W. The measured optical-to-optical and slope efficiencies are 44.5% and 51.4%, respectively. The high laser efficiencies can be attributed to the two-for-one cross-relaxation process and the efficient thermal management of the AFB laser composites.

Analysis and mitigation of Mach-Zehnder modulator nonlinearity in coherent optical OFDM system in the presence of high peak power

Paper 7960-17 of Conference 7960
Date: Wednesday, 26 January 2011
Time: 2:20 PM – 2:40 PM

Author(s): Yanir London, Dan Sadot, Ben-Gurion Univ. of the Negev (Israel)
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The nonlinear effect of Mach-Zehnder modulator (MZM) in optical fiber under the presence high peak power of optical orthogonal frequency division multiplexing (OFDM) is investigated. A full optical coherent communication system is presented and analyzed numerically. A method to mitigate the nonlinear effect by means of digital pre-distortion is proposed. Inclusive quantitative analysis of the effect of peak to average power (PAPR) reduction on the performance of the proposed Optical-OFDM system is presented.

Phase unwrapping with PMF Sagnac loop filter in swept-source OCT

Paper 7889-75 of Conference 7889
Date: Wednesday, 26 January 2011
Time: 3:00 PM – 3:15 PM

Author(s): Jae Seok Park, Chang-Seok Kim, Myung-Yong Jeong, Pusan National Univ. (Korea, Republic of)
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We propose a novel phase unwrapping method of the phase-sensitive OCT imaging with wavelength-swept laser source. To remove a 2π ambiguity, multiple Gaussian subsets of broad swept-source range are easily induced using a polarization-maintaining fiber (PMF) Sagnac loop filter, which can control the center wavelength, subset spacing and the number of subset inside the broad range. As each subset can measure phase variations separately and combine each phase map again, we can calculate a height profile over a few micrometers without phase jumps in phase-sensitive OCT.

Unified cost effective next-generation passive optical network and IEEE 802.16m network architecture

Paper 7959-10 of Conference 7959
Date: Wednesday, 26 January 2011
Time: 3:20 PM – 3:40 PM

Author(s): Shahab Hussain, Syed R. Zaidi, Hasan Erkan, The City College of New York (United States); Ajaz Sana, Bronx Community College (United States)
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This paper presents the key features of the emerging Next Generation Passive Optical Network (NG-PON) and IEEE 802.16m based Mobile Worldwide Interoperability for Microwave Access (WiMAX) networks to build a unified cost effective next generation hybrid Fiber-Wireless network. NG converged-access solutions can meet the demand for cost, mobility, bandwidth, reliability, security, and flexibility. NG-PON and 4th Generation (4G) Mobile WiMAX unified architecture enables differentiated bandwidth allocation to end users and can provide more network range and capacity at reduced operational cost.

Unified cost effective next-generation passive optical network and IEEE 802.16m network architecture

Paper 7958-10 of Conference 7958
Date: Wednesday, 26 January 2011
Time: 3:20 PM – 3:40 PM

Author(s): Shahab Hussain, Syed R. Zaidi, Hasan Erkan, The City College of New York (United States); Ajaz Sana, Bronx Community College (United States)
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This paper presents the key features of the emerging Next Generation Passive Optical Network (NG-PON) and IEEE 802.16m based Mobile Worldwide Interoperability for Microwave Access (WiMAX) networks to build a unified cost effective next generation hybrid Fiber-Wireless network. NG converged-access solutions can meet the demand for cost, mobility, bandwidth, reliability, security, and flexibility. NG-PON and 4th Generation (4G) Mobile WiMAX unified architecture enables differentiated bandwidth allocation to end users and can provide more network range and capacity at reduced operational cost.

Chromatic dispersion measurement of nano-silicon waveguides using a white-light interferometry method

Paper 7942-26 of Conference 7942
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Seung-Hwan Kim, Seoung Hun Lee, Dong Wook Kim, Kyong-Hon Kim, El-Hang Lee, Inha Univ. (Korea, Republic of); Jong-Moo Lee, Electronics and Telecommunications Research Institute (Korea, Republic of)
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Conventional methods to measure the chromatic dispersion of the optical fibers are time-of-flight methods, phase shift measurement method, and optical interferometer methods. These methods are good for the dispersion measurement of long-fiber samples, typically longer than one meter or several tens of centimeters. In this paper we report experimentally measured chromatic dispersion coefficient spectrum of a silicon nano-waveguide of 5 mm length with a white-light Mach-Zehnder interferometry method.

Next generation wireless technology WiMAX and its integration with EPON

Paper 7958-20 of Conference 7958
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Syed R. Zaidi, Shahab Hussain, Hasan Erkan, The City College of New York (United States); Ajaz Sana, Bronx Community College (United States); Aparicio Carranza, New York City College of Technology (United States)
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Integration of next generation wireless technologies i.e., WiMAX (Worldwide Interoperability for Microwave Access) and or LTE (Long Term Evolution) with EPON is a brilliant concept that gives users the best of two worlds, wireless and wired. WiMAX gives users the convenience of mobility while integration with EPON gives theoretically unlimited bandwidth of fiber optic cable in backhaul. This paper investigates WiMAX and EPON technologies. At the end different scenarios of integration of EPON with WiMAX are discussed and optimal QOS mapping scheme is proposed for the integration of EPON and WiMAX.

Optical current sensors comprised of polymeric waveguide components

Paper 7941-43 of Conference 7941
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Woo-Sung Chu, Ji-Hyang Jang, Jun-Whee Kim, Kyung-Jo Kim, Min-Cheol Oh, Pusan National Univ. (Korea, Republic of)
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Integrated optical current sensors based on polarization rotated reflection interferometry are demonstrated by incorporating polymeric optical waveguide components. Polarization maintaining 3-dB couplers, TE-pass waveguide polarizers, thermo-optic phase modulators and half-wave plates are designed and fabricated to be used to construct the optical current sensors. The phase difference between the two circularly polarized waves imposed by the Faraday effect of the optical fiber is detected using the interferometric optical sensor consisting of the polymeric components. The reflection interferometer comprising the polymer waveguide components operates with good linearity proportional to the monitoring current.

Novel single photon sources in diamond

Paper 7948-45 of Conference 7948
Date: Thursday, 27 January 2011
Time: 1:55 PM – 2:20 PM

Author(s): Igor Aharonovich, Stefania Castelletto, Univ. of Melbourne (Australia); David Simpson, Brant Gibson, Alastair Stacey, Julius Orwa, Brett Johnson, The Univ. of Melbourne (Australia); Snjezana Tomljenovic-Hanic, The Univ. of Sydney (Australia); Jeff McCallum, Andrew Greentree, Lloyd Hollenberg, Steven Prawer, The Univ. of Melbourne (Australia)
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Recently, we have discovered centres in diamond with improved single photon properties over NV. In particular we have identified a family of chromium-related centres. They are relatively easy to manufacture, have short lifetimes (a few nanoseconds), no photo-blinking, and some show ideal two-state emission. With high Huang-Rhys factors and emission around 750nm, prospects for fiber integration are good. Here we describe these centers' properties, growth conditions, and prospects for applications such as quantum key distribution.

Comparison of skin responses from macroscopic and microscopic UV challenges

Paper 7883A-15 of Conference 7883A
Date: Saturday, 22 January 2011
Time: 2:40 PM – 3:00 PM

Author(s): InSeok Seo, Paulo R. Bargo, Melissa Chu, Eduardo C. Ruvolo, Jr., Nikiforos Kollias, Johnson & Johnson CPPW (United States)
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The traditional phototest to determine the sensitivity of skin to ultraviolet radiation has been performed in skin areas ranging 1 cm2 and 1 in2. There have been reports that the apparent sensitivity of the skin, expressed as erythema, decreases for areas of the order of 1 mm2 and smaller. In this study, we investigated the responses of human skin to solar-simulated radiation with a beam diameter of 200 m (0.03 mm2). Twelve human subjects of skin phototype I-IV were exposed to solar-simulated radiation on their upper inner arm or on their lower back with a series of doses in increments of 20% in order to determine the threshold dose to induce a minimal perceptible erythema response (MED). Each dose was delivered with a liquid light guide of 8 mm diameter and with quartz optical fibers of 200 mm diameter. The resulting skin responses were evaluated visually and investigated with a reflectance confocal microscope and imaging. The erythema response to the microscopic challenge was always diffuse with no clear boundaries extending to several times the exposed site diameter at doses greater than 2MED. The pigment responses induced by UV exposure were observed both by video microscope and confocal microscope on 5-7 days after exposure. Unlike the erythema response, pigment responses to the microscopic challenge were always confined within the irradiated sites and the produced melanin is non-uniformly granulated and different from constitutive melanin in size and shape. The skin returned to normal appearance from the microscopic challenge after two weeks of exposure while change in appearance for the larger areas persisted for several weeks to months. This new modality of testing provides the possibility to study skin at the microscopic level with a rapid recovery following challenge.

Hyperspectral imaging and modeling of bruises

Paper 7892-6 of Conference 7892
Date: Saturday, 22 January 2011
Time: 9:50 AM – 10:10 AM

Author(s): Barbara Stam, Martin J. van Gemert, Ton G. van Leeuwen, Maurice C. Aalders, Jr., Academisch Medisch Ctr. (Netherlands)
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We developed a numerical 3D model to simulate the spatial kinetics of hemoglobin and bilirubin during the formation and healing of bruises. Model bruises were used to develop a method to determine the age of bruises using the different spatio-temporal dynamics of hemoglobin and bilirubin, which are due to difference in diffusivity. We did spatially resolved reflectance measurements on real bruises using a hyper spectral imaging system and a fiber based system. Combining the spectral information of chromophore concentrations with the spatial information of the chromophores allows precise simulation of the kinetics in these real bruises and accurate age determination.

Dual-modality catheter for optical frequency domain imaging and near-infrared fluorescence imaging

Paper 7883D-77 of Conference 7883D
Date: Saturday, 22 January 2011
Time: 11:20 AM – 11:40 AM

Author(s): HongKi Yoo, Jin Won Kim, Milen S. Shishkov, Eman namati, Massachusetts General Hospital (United States); Theodore F. Morse, The Boston Univ. Photonics Ctr. (United States); Roman L. Shubochkin, Boston Univ. (United States); Jason R. McCarthy, Brett E. Bouma, Farouc A. Jaffer M.D., Guillermo J. Tearney, Massachusetts General Hospital (United States)
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We report a dual modality intra-arterial catheter system that simultaneously obtains co-registered optical frequency domain imaging (OFDI) and near-infrared fluorescence (NIRF) imaging from artery wall in vivo. The catheter is comprised of a double-clad fiber, contained within a rotating cable and a transparent sheath. Comprehensive 3D datasets were acquired from a coronary stent, deployed in an iliac artery of a living rabbit. The results clearly delineate the microstructures of the luminal arterial wall, metallic stent struts, and thrombus as well as NIRF emission. The NIRF signals show strong correspondence with the OFDI. This novel catheter could open up new opportunities for improving our understanding of coronary atherosclerosis.

Corral trap confinement and manipulation of single molecules

Paper 7905-8 of Conference 7905
Date: Saturday, 22 January 2011
Time: 11:40 AM – 12:05 PM

Author(s): Jorg C. Woehl, Christine A. Carlson, Univ. of Wisconsin-Milwaukee (United States)
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The corral trap is a novel tool for the trapping and manipulation of micro- and nanoscale particles and single molecules in solution over extended periods of time. We will compare different approaches for corral trap fabrication and discuss trapping experiments with a stationary corral trap, carried out on nanoscale particles and single DNA molecules. True manipulation of single molecules, however, requires not only the confinement of the object under investigation, but also the capability to move the trapped object across the sample surface; one possible approach towards this objective based on fiber-optic probes will be discussed.

Three-dimensional imaging of dental hard tissues with Fourier domain optical coherence tomography

Paper 7883F-131 of Conference 7883F
Date: Saturday, 22 January 2011
Time: 1:50 PM – 2:20 PM

Author(s): Yueli Chen, Agiltron, Inc. (United States); Yi Yang, Univ. of Connecticut (United States); Jing J. Ma, Jun J. Yan, Yuanxin Shou, Agiltron, Inc. (United States); Tianheng Wang, Univ. of Connecticut (United States); Jing Zhao, Agiltron, Inc. (United States); Quing Zhu, Univ. of Connecticut (United States)
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A fiber optical coherence tomography (OCT) probe is used for three dimensional dental imaging. The probe has a lightweight miniaturized design with a size of a pen to facilitate clinic in vivo diagnostics. The probe is interfaced with a Fourier domain optical coherence tomography at 20K axial scanning rate. We scanned surface of tooth samples from occlusal, buccal, lingual, mesial, and distal orientations. The image results show better resolution and contrast compared to gold standard dental radiography (X-ray). Three dimensional imaging provides full information of tooth surface where a majority of caries affection occurs. We are able to visualize the topology of tooth surface as well as the two dimensional dentin-enamel junction (DEJ) inside the tooth.

Characterizing variability in Raman Spectra of benign lesions toward cancer detection in skin

Paper 7883A-13 of Conference 7883A
Date: Saturday, 22 January 2011
Time: 2:00 PM – 2:20 PM

Author(s): Isaac J. Pence, Chetan A. Patil, Elizabeth Vargis, Brittany Caldwell, Darrel L. Ellis M.D., Anita Mahadevan-Jansen, Vanderbilt Univ. (United States)
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Raman Spectroscopy has demonstrated the potential to perform non-invasive classification of skin lesions however, the high level of physiological and anatomical variability in benign skin can complicate optical diagnosis. A thorough understanding of benign lesion's variability both between patients and within a single patient may lead to improved diagnostic outcomes. Here, we present a fiber-optic probe-based 785nm Raman Spectroscopy study of 164 patients with benign lesions and report an analysis of spectral variability. Characterization of these classes of skin is a critical first step in the formation of a spectral database that will enable future comparisons with malignant lesions.

Comprehensive OCT imaging of retinal microsvasculature without adaptive optics

Paper 7885-18 of Conference 7885
Date: Saturday, 22 January 2011
Time: 3:00 PM – 3:15 PM

Author(s): Rainer A. Leitgeb, Tilman Schmoll, Amardeep S. G. Singh, Eva Diettrich, Georg Langs, Medizinische Univ. Wien (Austria)
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Novel CMOS detector based spectral OCT has recently demonstrated its ability to image at acquisition speeds of 200kHz comprehensive details due to the virtual lack of motion artifacts. We applied this system to the retina and achieved high resolution imaging with 5µm x 3µm transverse and axial resolution. Such resolution allows observing microscopic details such as photoreceptor cone mosaic, nerve fiber bundles, and the capillary bed without applying adaptive optics instrumentation. Doppler methods have been successfully applied to extract the capillary network. We demonstrate how already on the intensity level para-foveal capillary structures can be segmented using learning post-processing algorithms.

Photobiomodulatory effects of He-Ne laser on excision wounds

Paper 7887-16 of Conference 7887
Date: Saturday, 22 January 2011
Time: 4:00 PM – 4:20 PM

Author(s): Vijendra Prabhu, Satish B. S. Rao, Manipal Univ. (India); Pramod Kumar, ; Lakshmi Rao, Manipal University (India); Krishna K. Mahato, Manipal Univ. (India)
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The present study was aimed to investigate the promotive effect of LLLT on excision wounds in Swiss albino mice using optical fiber probe based light device. Excision wounds were illuminated with single exposure of various laser doses except controls. Further, optimal dose of 2 J/cm2 was applied to excision wounds at different post-wounding treatment schedules. Progression of wound contraction, mean wound healing time and biochemical estimations from wound ground tissue were assessed. Granulation tissues were stained with Hematoxylin-Eosin staining and analyzed. Results demonstrated optimum tissue regeneration at 2 J/cm2 dose, applied immediately after the wounding as compared to controls.

Sutureless closure of scleral wounds in animal models by the use of laser-welded biocompatible patches

Paper 7885-24 of Conference 7885
Date: Saturday, 22 January 2011
Time: 5:00 PM – 5:15 PM

Author(s): Francesca Rossi, Paolo Matteini, Istituto di Fisica Applicata Nello Carrara (Italy); Luca Menabuoni M.D., Ivo Lenzetti, Azienda USL 4 (Italy); Roberto Pini, Istituto di Fisica Applicata Nello Carrara (Italy)
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We propose a sutureless, laser assisted technique for the closure of ocular wounds. It is based on the use of biocompatible, biopolymeric patches, that can be positioned as a plaster and then laser welded in their final position. ICG is included during preparation of the patches, thus resulting in high absorption at 810 nm. The laser is a diode (810 nm), equipped with a 200 micrometer core diameter optical fiber. The result is an immediate closure of the wound. The same procedure was performed with an amniotic membrane, previously stained with a water solution of ICG.

Nonlinear enhancement in photonic crystal waveguide with spot-size converter

Paper 7949-1 of Conference 7949
Date: Sunday, 23 January 2011
Time: 8:10 AM – 8:25 AM

Author(s): Mizuki Shinkawa, Yokohama National Univ. (Japan); Toshihiko Baba, Yokohama National Univ. (United States)
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This paper reports clear nonlinear enhancement in a SOI photonic crystal waveguide slow light device. We integrated the device with spot-size converters using CMOS process, which reduces the coupling loss from lensed fiber to 3 dB. Therefore, the highest coupled power, maintaining the linearity in external setup, is enhanced and nonlinearities in the device become clearer. We observed two-photon absorption for a milliwatt order pulse peak. We also observed the self-phase modulation and four-wave mixing. These results indicate that such slow light can be exploited for low-power compact optical limiters and wavelength converters.

A 1.2 mm diameter integrated photoacoustic and ultrasonic catheter for intravascular imaging

Paper 7899-3 of Conference 7899
Date: Sunday, 23 January 2011
Time: 8:45 AM – 9:00 AM

Author(s): Krista Jansen, Geert Springeling, Robert Beurskens, Erasmus MC (Netherlands); Antonius F. W. van der Steen, Erasmus MC (Netherlands) and Interuniversity Cardiology Institute (Netherlands); Gijs van Soest, Erasmus MC (Netherlands)
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We developed an integrated intravascular photoacoustics (IVPA) and ultrasound (IVUS) catheter to image atherosclerotic plaque structure and composition, important determinants of plaque vulnerability. Our catheter comprises an angle-polished optical fiber and a 30 MHz single-element transducer. The ultrasonic transducer was optically isolated to eliminate artifacts in the PA image. We quantified its imaging performance on isolated point targets and in a vessel phantom. Point spread function widths were 0.11 mm/0.55 mm (PA; axial/lateral) and 0.089 mm/0.42 mm (US); signal to noise ratios were 50 dB (PA) and 54 dB (US). Further diameter reduction to 1.0 mm will be discussed.

The effect of collimator lenses on the performance of an optical coherence tomography system

Paper 7885-32 of Conference 7885
Date: Sunday, 23 January 2011
Time: 8:45 AM – 9:00 AM

Author(s): Pauli Fält, Univ. of Eastern Finland (Finland) and Utsunomiya Univ. (Japan); Robert J. Zawadzki, UC Davis Medical Ctr. (United States); Barry Cense, Utsunomiya Univ. (Japan)
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The effect of using collimator lenses with different focal lengths on the performance of an adaptive optics Fourier-domain optical coherence tomography (AO-Fd-OCT) system is studied. In vivo AO-Fd-OCT scans of a healthy human retina are taken separately for different collimator lenses. Although shorter focal length lenses provide a smaller beam diameter at the pupil of the eye, and therefore a larger diffraction-limited spot size, on the return path the shorter focal length collimators demonstrate a better performance focusing the sinc-function intensity distribution returning from the eye on the fiber tip. The results might have applications in the OCT-imaging of challenging cases.

Toward in-vivo photoacoustic imaging of human ovarian tissue for cancer detection

Paper 7899-7 of Conference 7899
Date: Sunday, 23 January 2011
Time: 9:45 AM – 10:00 AM

Author(s): Andres Aguirre, Yasaman Ardeshirpour, Univ. of Connecticut (United States); Mary M. Sanders, Molly A. Brewer, Univ. of Connecticut Health Ctr. (United States); Quing Zhu, Univ. of Connecticut (United States)
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We have investigated the potential role of photoacoustic imaging in ovarian cancer detection. We estimated the light absorption from thirty-three ex-vivo human ovaries. Malignant postmenopausal ovaries showed higher light absorption than normal ones with sensitivity of 83% and a specificity of 83%. In an effort to bring this technique closer to clinics, we have developed a photoacoustic transvaginal probe. A fiber coupling assembly has been developed to deliver the light around the transducer in reflection geometry. Co-registered ultrasound and photoacoustic images of swine ovaries through vagina muscle wall demonstrate the potential of photoacoustic imaging for non-invasively detection of ovarian cancer.

Miniature 3D confocal microendoscope used to in-vivo identification of Eosinophils trigger symptoms

Paper 7893-6 of Conference 7893
Date: Sunday, 23 January 2011
Time: 10:20 AM – 10:40 AM

Author(s): Zhongyao Liu, Johannes Domke, Zhen Qiu, Nastaran Safdarian, Kenn Oldham, Emily Wang, Thomas D. Wang M.D., Univ. of Michigan (United States)
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A novel fiber-based miniature confocal microendoscope has been developed to image the eosinophils in vivo. 471nm laser is used for excitation. The main components of the confocal microendoscope include a MEMs scanning mirror, a miniature aspheric relay lenses system, and a high NA (0.6) GRIN lens. The outside diameter of the probe is 8mm, the field of view is larger than 270µm(x) X 260µm(y) X 240µm (z) and the lateral and axial resolution is ~1 µm and ~5 µm, respectively. The image of fluorescent beads and live eosinophils cell are demonstrated.

In-vivo experimental study on laser welded ICG-loaded chitosan patches for vessel repair

Paper 7883D-93 of Conference 7883D
Date: Sunday, 23 January 2011
Time: 11:00 AM – 11:20 AM

Author(s): Francesca Rossi, Paolo Matteini, Istituto di Fisica Applicata Nello Carrara (Italy); Giuseppe Esposito, Alessio Albanese M.D., Alfredo Puca M.D., Giulio Maira, Univ. Cattolica del Sacro Cuore (Italy); Roberto Pini, Istituto di Fisica Applicata Nello Carrara (Italy); Giacomo Rossi, Univ. degli Studi di Camerino (Italy)
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We present the first in vivo application of laser welded biopolymeric patches for vessel repair. A 3 mm linear lesion was carried out on rabbit carotid artery. ICG-loaded chitosan films were prepared. They were used to wrap the whole length of the cut, and then they were laser welded by delivering single laser spots (diode laser emitting at 810 nm, 300 µm diameter optical fiber) to induce local patch/tissue adhesion by photothermal effect. Immediate closure of the wound was induced. Histological examinations during follow up were performed, evidencing the reduction of inflammatory reactions and a good healing process.

SHG as a robust means to quantify changes in collagen deposition that accompany cancer progression

Paper 7903-10 of Conference 7903
Date: Sunday, 23 January 2011
Time: 1:05 PM – 1:25 PM

Author(s): Paul J. Campagnola, Visar Ajeti, Suzanne M. Ponik, Carolyn Pehlke, Kevin W. Eliceiri, Patricia J. Keely, Univ. of Wisconsin-Madison (United States); Molly A. Brewer, Michael Tadros, Kooroosh Moezardalan, John Birk, Univ. of Connecticut Health Ctr. (United States)
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We show that alterations in collagen deposition in ovarian, colon, and breast cancer have commonalities that can be effectively probed quantitatively by SHG microscopy. All these cancers display increased collagen deposition, known as desmoplasia. Additionally, analysis of the forward-backward (F/B) measurements reveal changes in the fibril arrangement in ovarian cancer and in vitro models of collagen matrices, demonstrating that SHG is sensitive to sub-resolution changes in assembly (~50-100 nm). These cancers show strong differences in fiber alignment relative to normal tissues, where these may facilitate invasion. These findings point to the applicability of SHG as a clinical diagnostic tool.

A non-contact time-domain scanning brain imaging system: results of proof of principle tests

Paper 7896-11 of Conference 7896
Date: Sunday, 23 January 2011
Time: 1:30 PM – 1:50 PM

Author(s): Mikhail Mazurenka, Alexander Jelzow, Heidrun Wabnitz, Physikalisch-Technische Bundesanstalt (Germany); Davide Contini, Lorenzo Spinelli, Antonio Pifferi, Rinaldo Cubeddu, Alberto Dalla Mora, Alberto Tosi, Politecnico di Milano (Italy); Franco Zappa, Micro Photon Devices S.r.l. (Italy) and Politecnico di Milano (Italy); Rainer Macdonald, Physikalisch-Technische Bundesanstalt (Germany)
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We report tests results of the proof of principle stage in the development of a non-contact time-domain brain scanning system. The system is designed for the recently devised null-distance approach and utilizes polarization-sensitive detection and a fast-gated single-photon avalanche photodiode to detect late photons only, bearing information about deeper layers of the head. The measured depth sensitivity and spatial resolution of the new system are similar to those reported earlier for a fiber-based instrument with the same detector. The development of a fully operational prototype is in progress. The envisaged applications are in area of functional brain studies.

Aptamer-based localized surface plasmon resonance sensor for monitoring glycated proteins

Paper 7911-13 of Conference 7911
Date: Sunday, 23 January 2011
Time: 2:00 PM – 2:20 PM

Author(s): Rui Zheng, Brent D. Cameron, The Univ. of Toledo (United States)
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A fiber optic based aptamer functionalized localized surface plasmon resonance sensor has been developed for the rapid, small volume and label-free detection of glycated proteins. The ability to monitor such proteins in the body could facilitate the diagnosis and treatment of diabetes. The sensor was fabricated by nanosphere lithography with excellent reproducibility. The performance of the sensor is evaluated using a custom developed flow cell with competitive samples loaded. Results are compared to the simulation of the discrete dipole approximation (DDA). Further development of the sensor will involve functionalizing the nano-noble metal with length specified aptamers.

Navy Laser Weapon System (LaWS) prototype development and testing

Paper 7915-11 of Conference 7915
Date: Sunday, 23 January 2011
Time: 2:00 PM – 2:30 PM

Author(s): Brian J. Hankla, Naval Surface Warfare Ctr. Dahlgren Div. (United States)
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The Navy's Laser Weapon System (LaWS) is a NAVSEA weapon development effort with the primary objective to add a high energy laser (HEL) weapon capability to the Navy Phalanx Close-in-Weapon System (CIWS). Over the past few years, system components and a full weapon prototype have been tested in increasingly challenging conditions. These tests have been designed to demonstrate the technical readiness of many of the key technologies, including fiber lasers, for use in Navy weapon applications. The most recent tests of the prototype occurred in May and June 2010 under very stressing, but typical, maritime conditions. This presentation will give an update of the status of the effort, show results of the recent live-fire testing, and discuss many of the system challenges that are currently being addressed.

Large dynamic range electromagnetic field sensor based on domain inverted electro-optic polymer directional coupler

Paper 7936-16 of Conference 7936
Date: Sunday, 23 January 2011
Time: 2:50 PM – 3:20 PM

Author(s): Alan X. Wang, Omega Optics, Inc. (United States); Beom-Suk Lee, Ray T. Chen, The Univ. of Texas at Austin (United States)
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A large dynamic range electromagnetic field sensor based on domain inverted electro-optic polymer directional coupler is designed and fabricated. The length of the inverted domains is numerically optimized to obtain a linear transfer function, and a large dynamic range of 119dB/ Hz2/3. To achieve higher E-O efficiency, pulse poling voltage with inverse polarity is applied to generate a push-pull drive for the device. The fabricated photonic EMF sensor is coupled with polarization maintenance (PM) fiber and driven by electromagnetic waves from a horn antenna. The sensor shows a uniform response to electromagnetic waves from DC to 20GHz.

Hollow waveguides for the transmission of quantum cascade laser (QCL) energy for spectroscopic applications

Paper 7894-42 of Conference 7894
Date: Sunday, 23 January 2011
Time: 4:10 PM – 4:30 PM

Author(s): J. A. Harrington, C. M. Bledt, Rutgers Univ. (United States); J. M. Kriesel, Opto Knowledge Systems, Inc. (United States)
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The development and evaluation of hollow glass waveguides (HGWs) for use in Long-Wave Infrared (LWIR) spectroscopy systems is described. The LWIR wavelength region (8 to 12 microns) is useful for detecting trace chemical compounds indicative of weapons of mass destruction (WMD). Fiber optics that can operate in the LWIR region are a key enabling technology needed to improve the utility and effectiveness of detection systems. HGWs have been used for IR laser deliver for many years but only recently in conjunction with QCL sources for the dedicated detection of trace gases. This paper focuses on recent developments in HGW technology aimed specifically for the transmission of single-mode radiation from QCL sources. The losses for the HGWs are as low as 0.5 dB/m for a 485 micron bore HGW and the beam quality is preserved even on bending the 300 micron bore guides. Results will be presented for straight and bent HGWs along with some key modal properties of the guides. Specifically, mode filtering and the preservation of single-mode transmission will be discussed.

Wavelength-swept laser-based spectrally encoded fluorescence imaging

Paper 7893-21 of Conference 7893
Date: Sunday, 23 January 2011
Time: 5:20 PM – 5:40 PM

Author(s): Mathias Strupler, Nadir Goulamhoussen, Etienne De Montigny, Caroline Boudoux, Ecole Polytechnique de Montréal (Canada)
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We developed a novel fluorescence imaging technique based on spectral encoding using a wavelength-swept laser (wsl). We simultaneously acquired fluorescence and reflectance images of a textile sample stained with NIR quantum dots at 9920 lines of 1024 pixels per second, orders of magnitude faster than the previously reported scheme based on a broadband laser and wavelength dependent amplitude modulation. In order to expand the technique to FDA approved fluorophores, we developed a wsl centered at 780nm (30nm bandwidth, 29 kHz scanning, 120 mW output power). This approach could be combined with a dual-clad fiber coupler for endoscopic implementation.

A low-cost multi-wavelength tomography system based on LED sources

Paper 7896-96 of Conference 7896
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Aaron Chen, Andres Aguirre, Umar S. Alqasemi, Quing Zhu, Univ. of Connecticut (United States)
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We present a multi-wavelength DC system using Light Emitting Diode (LED) sources of four wavelengths in the near infrared range. These LEDs are commercially available, much cheaper than laser diodes, and have adequate power to probe deeply seated lesions. In our system, 8 groups of LEDs of four wavelengths were deployed on a hand-held probe and 14 PMT detectors were fiber coupled to the probe. A co-registered ultrasound array attached to the probe provided lesion structure information. Experiments evaluated the performance of the LED based DC system and the laser-diode based frequency domain system and the results were comparable.

Light distribution in turbid media: an approach based on matrices

Paper 7886-42 of Conference 7886
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Lilian T. Moriyama, Univ. de São Paulo (Brazil); Emery C. Cabral Correia Lins, Univ. Federal do ABC (Brazil); Cristina Kurachi, Vanderlei S. Bagnato, Univ. de São Paulo (Brazil)
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In this study, we have developed an empirical method to determine light distribution in optical phantom. This method is based on experimental measurements of light intensity as a function of position inside the medium. Milk solution and fat emulsion were chosen as turbid media and a HeNe laser at 633nm was used as light source. Light intensity within the phantoms was detected by an isotropic fiber optic probe. The data were collected for a collimated narrow laser beam and arranged in a tridimensional matrix. Using this matrix, simple mathematical operations were used to simulate different conditions of irradiation geometry.

Role of Yb3+ ions in the IR to visible upconversion of Er3+ ions in LTT glasses

Paper 7940-19 of Conference 7940
Date: Monday, 24 January 2011
Time: 8:20 AM – 8:45 AM

Author(s): Mohan Babu A, Suresh Kumar Jakka, Sri Venkateswara Univ. (India); B.C. Jamalaiah, Pukyong National Univ. (Korea, Republic of); Neeraj Kumar Giri, S.B. Rai, Banaras Hindu Univ. (India); Rama Moorthy Lalapeta, Sri Venkateswara Univ. (India)
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Detailed spectroscopic and upconversion flourescence properties of singly doped Er3+ and co-doped Er3+/Yb3+ ions in lead tungsten tellurite (LTT) glasses have been studied under 976 nm excitation. Judd-Ofelt (J-O) analysis has been performed for the absorption spectral intensities of Er3+and Er3+/Yb3+ absorption bands. Spontaneous emission probabilities (AR), radiative lifetimes (τR ) and branching ratios were calculated by using the phenomenological J-O intensity parameters. The important role of Yb3+ ions in the upconversion intensity, and the concentration effect of Yb3+ ions on blue, green and red emissions has been discussed. From these results it is concluded that lead tungsten tellurite glasses could be used as promising host materials for the design and development of optical fiber amplifiers and upconversion lasers.

High-power 1.25 μm InAs QD VECSEL based on resonant periodic gain structure

Paper 7919-3 of Conference 7919
Date: Monday, 24 January 2011
Time: 9:15 AM – 9:30 AM

Author(s): Alexander R. Albrecht, Thomas J. Rotter, Christopher P. Hains, Andreas Stintz, The Univ. of New Mexico (United States); Tsuei-Lian Wang, The Univ. of Arizona (United States); Yushi Kaneda, Jerome V. Moloney, College of Optical Sciences, The Univ. of Arizona (United States); Kevin J. Malloy, Ganesh Balakrishnan, The Univ. of New Mexico (United States)
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We compare an InAs quantum dot (QD) VECSEL design consisting of 4 groups of 3 closely spaced QD layers with a resonant periodic gain (RPG) structure, where each of the 12 QD layers is placed at a separate field antinode. This increased the spacing between the QDs, reducing strain and greatly improving device performance. For thermal management, the GaAs substrate was thinned and indium bonded to CVD diamond. A fiber-coupled 808 nm diode laser was used as pump source, a 1% transmission output coupler completed the cavity. CW output powers over 3 W at 1250 nm were achieved.

Record CW-brightness from a single, 20% fill-factor, 1-cm laser-diode bar at 20°C

Paper 7918-20 of Conference 7918
Date: Monday, 24 January 2011
Time: 9:30 AM – 9:50 AM

Author(s): Aland K. Chin, Somerville Laser Technology, LLC. (United States); Maciej T. Knapczyk, Jonah H. Jacob, Henry Eppich, Keith D. F. Lang, Richard H. Chin, Science Research Lab., Inc. (United States)
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A record, 240W, CW output-power has been achieved for a single, 1cm-wide, 3.5mm cavity-length, 20% fill-factor, 976nm, laser-diode bar operated at 20°C. The remarkable laser-bar performance was in part the result of a novel EPIC (Enhanced Performance Impingement Cooler) heat-sink with a thermal resistance of 1.6x10-2K/W. The superb thermal-management resulted in record brightness for a laser bar, i.e. a slow-axis divergence of 10° (95% power containment angle) and a collimated fast-axis beam-pointing of less than 1mrad was achieved at 200W output power, resulting in an expected coupling efficiency of more than 85% into a 200μm core, 0.22NA fiber.

Topical HpD-mediated photodynamic therapy for DMBA-induced hamster buccal pouch malignant lesions

Paper 7900-3 of Conference 7900
Date: Monday, 24 January 2011
Time: 10:00 AM – 10:20 AM

Author(s): Ivy Y. Hsu, Chung Yuan Christian Univ. (Taiwan); Chun-Pin Chiang D.D.S., National Taiwan Univ. (Taiwan); Junn-Liang Chang M.D., Kuang-Ting Liu, Taoyuan Armed Forces General Hospital (Taiwan); Chung-Ji Liu M.D., National Yang-Ming Univ. (Taiwan) and Mackay Memorial Hospital (Taiwan) and MacKay Medicine, Nursing and Management College (Taiwan); Chih-Ping Chen M.D., Mackay Memorial Hospital (Taiwan); Jeng-Woei Lee, Tzu Chi Univ. (Taiwan)
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Oral cancer has becomes the most prominent cancer disease in recent years in Taiwan. In previous studies showed that hematoporphyrin derivative (HPD), has demonstrated effective PDT results on human head and neck disease studies. To avoid the systemic phototoxic effect of HpD, this study was designed to use a topical HpD-mediated PDT for treatment of DMBA-induced hamster buccal pouch cancerous lesions. DMBA was applied to one of the buccal pouches of hamsters thrice a week. These DMBA-induced cancerous lesions were used for testing the efficacy of topical HpD-mediated PDT. The cancerous lesions in hamsters were then treated with topical HpD-mediated PDT using the portable light source at 635 nm fiber-guided light device. Visual examination demonstrated that topical HpD-mediated PDT was an applicable treatment modality for DMBA-induced hamster buccal pouch cancerous lesions.

Measuring joint-cartilage thickness using reflectance spectroscopy noninvasively and in real time

Paper 7890-7 of Conference 7890
Date: Monday, 24 January 2011
Time: 10:30 AM – 10:50 AM

Author(s): Murat Canpolat, Akdeniz Univ. (Turkey); Tuba Denkceken, Cosar Karagol, Ahmet T. Aydin, Akdeniz Univ (Turkey)
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Joint cartilage thickness has been estimated using spatially resolved steady-state reflectance spectroscopy noninvasively and in-real time. The system was consists of a miniature UV-VIS spectrometer, a halogen tungsten light source, and optical fiber probe with six 400 m diameter fibers. Total 40 calf's patella were grouped into four; the firs group was the control group and cartilages were not damaged, in the 2nd, 3rd and 4th groups cartilage thickness was reduced approximately 25%, 50% and 100% respectively. The system has potential for the assessment of the cartilage thickness through an arthroscope channel without giving dame to the cartilage in real-time.

High power thin disk Ho:YAG laser

Paper 7912-12 of Conference 7912
Date: Monday, 24 January 2011
Time: 10:40 AM – 11:00 AM

Author(s): Jochen Speiser, Günther Renz, Adolf Giesen, Deutsches Zentrum für Luft- und Raumfahrt e.V. (Germany)
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The thin-disk laser is a successful concept for high output power and/or high pulse energy, high efficiency and good beam quality in the 1 µm range. Holmium-doped materials are a promising approach to transform this success to the 2 μm range. Ho:YAG is especially interesting for high pulse energies due to the long fluorescence lifetime (~ 8 ms) which provides good energy storage capabilities. We have realized a Ho:YAG thin-disk laser with a cw output power of 15 W at 2.09 μm and a maximum optical-to-optical efficiency of 37%. The laser was pumped with a Tm-fiber laser.

In vivo monitoring of vessel density pattern in skin phantoms for the application of early sign of shock detection by using diffuse reflectance spectroscopy

Paper 7890-8 of Conference 7890
Date: Monday, 24 January 2011
Time: 10:50 AM – 11:10 AM

Author(s): Rajesh V. Kanawade, Friedrich-Alexander-Univ. Erlangen-Nürnberg (Germany); Gennadi Sayko, Friedrich-Alexander Univ. Erlangen-Nürnberg (Germany); Michael Schmidt, Alexandre Douplik, Friedrich-Alexander-Univ. Erlangen-Nürnberg (Germany)
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Broadband diffuse reflectance spectroscopy is a reliable non-invasive or minimally invasive medical diagnostic modality potentially used for measurements of tissue reduced/-oxy hemoglobin. Medical shock is a common cause of trauma patient's death in Intensive Care Units (ICU). Still the mortality due to shock is unacceptably high, because of the monitoring/ diagnostic techniques limitations and short time span of shock development. In this paper we introduce a method of monitoring of the vessel density pattern, using diffuse reflectance measurement. The setup contains a spatially resolved optical fiber probe coupled to supersensitive spectrometer and high power light source. The measurement parameters comprising reduced /- oxyhemoglobin and oxygen saturation are exploited for vessel density spatial pattern detection. Real time monitoring of the vessel density spatial pattern will help to detect the early sign of shock development in intensive care units.

Four-dimensional peripheral lung dynamics assessed through catheter-based optical frequency domain imaging

Paper 7893-31 of Conference 7893
Date: Monday, 24 January 2011
Time: 11:10 AM – 11:30 AM

Author(s): Eman Namati, Carolin I. Unglert, Wellman Ctr. for Photomedicine (United States); Brett E. Bouma, Guillermo J. Tearney, Massachusetts General Hospital (United States)
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Investigating the dynamic structure and function of pulmonary alveoli is crucial for understanding the normal and diseased lung. Through a catheter based optical frequency domain imaging system we investigate the dynamic relationship between alveoli and small airways in an isolated swine lung model. A fiber optic catheter was inserted through the trachea and down into the peripheral lung where high-speed helical pullbacks were performed at multiple inflation and deflation pressures. For the first time to our knowledge, catheter based OFDI of dynamic alveolar and small airway measurements have been simultaneously made during air filled ventilation, providing insight into this organ.


Ultra-wide-field lensfree fluorescent imaging of caenorhabditis elegans on a chip

Paper 7902-42 of Conference 7902
Date: Monday, 24 January 2011
Time: 11:20 AM – 11:40 AM

Author(s): Ahmet F. Coskun, Ikbal Sencan, Ting-Wei Su, Aydogan Ozcan, Univ. of California, Los Angeles (United States)
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We introduce a high-throughput lensfree on-chip fluorescent imaging modality that can monitor labeled C. elegans samples over an ultra-wide field-of-view of >8cm2 with ~10um resolution. In this approach, the fluorescent emission from the nematode is collected by a fiber-optic-faceplate and is delivered to a wide-field sensor-array without the use of any lenses. To make up for the lack of lenses, the detected fluorescent distribution is then digitally reconstructed using compressive decoding to yield ~10um resolution over the entire imaging field-of-view (~8cm2). Such a high-throughput lensfree fluorescent imaging platform might be especially valuable for drug discovery, genome analysis and cancer research.

Imaging necrosis in mouse models of muscular dystrophy with three-dimensional optical coherence tomography

Paper 7889-12 of Conference 7889
Date: Monday, 24 January 2011
Time: 11:45 AM – 12:00 PM

Author(s): Blake R. Klyen, Thea Shavlakadze, Miranda D. Grounds, David D. Sampson, The Univ. of Western Australia (Australia)
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We report the use of three-dimensional optical coherence tomography (3D-OCT) in conjunction with Evans blue dye, a marker for muscle fiber permeability, used to guide the 3D-OCT imaging. We apply this to imaging mouse skeletal muscle tissue from exercise-induced damage models of dystropathology in human muscular dystrophy. Images are presented that show the ability of 3D-OCT to identify lesions, regions of necrosis and inflammation, within large volumes of skeletal muscle tissue, and differentiate these from the surrounding intact muscle fibers. These results demonstrate that 3D-OCT is a suitable modality for small animal imaging studies of muscular dystrophy.

Integrated multiplex CARS and two-photon fluorescence microscopy for imaging biological systems

Paper 7903-37 of Conference 7903
Date: Monday, 24 January 2011
Time: 1:49 PM – 2:01 PM

Author(s): Dong Li, Wei Zheng, Jianan Y. Qu, Hong Kong Univ. of Science and Technology (Hong Kong, China)
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A multimodal nonlinear optical microscopy that combines the multiplex coherent anti-stokes Raman scattering (M-CARS) signals with the two-photon excitation fluorescence (TPEF) has been developed. The excitation sources are a femtosecond laser and the broadband supercontinuum from photonic crystal fiber. The large non-resonant signals in the femotosecond laser excited CARS images was effectively suppressed by using a simple subtraction method. The nonlinear optical signals of M-CARS, TPEF, and second harmonic generation (SHG) are simultaneously excited and collected by a time- and wavelength-resolved detection capability. We demonstrate the multimodal imaging capability using the C.elegnas and 3T3-L1 cells as the living biological samples.

Thermal effect induced by interstitial irradiation of near-infrared laser with cylindrical diffuser

Paper 7900-10 of Conference 7900
Date: Monday, 24 January 2011
Time: 2:50 PM – 3:10 PM

Author(s): Wei R. Chen, Daniel Figueroa, Kelvin Le, Univ. of Central Oklahoma (United States); Xiaosong Li, Chinese PLA General Hospital (China); Jonny Walla, Univ. of Central Oklahoma (United States); Roman F. Wolf, The Univ. of Oklahoma Health Sciences Ctr. (United States); Hong Liu, The Univ. of Oklahoma (United States); Robert E. Nordquist, Wound Healing of Oklahoma, Inc. (United States); Tomas L. M. Hode, Immunophotonics, Inc. (United States)
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The present study is designed to investigate the thermal effect of interstitial irradiation using an 805-nm laser with a cylindrical diffuser, in order to overcome the limitations of the non-invasive mode of treatment. Gel phantom, chicken breast tissue, bovine liver and pig kidney, as well as in vivo rat tumors were irradiated using this system. The temperature increase was monitored by thermocouples that were inserted into the tissue at different sites around the cylinder fiber. Three-dimensional temperature distributions in target tissues during and after interstitial laser irradiation were also determined by magnetic resonance thermometry. The preliminary results showed that the output power of laser and the optical parameters of the target tissue determined the light distribution in tissue. These results will help us understand and control the thermal effect induced by interstitial laser irradiation.

Optical path of infrared neural stimulation in the guinea pig cochlea

Paper 7883G-160 of Conference 7883G
Date: Monday, 24 January 2011
Time: 3:10 PM – 3:30 PM

Author(s): Laura E. Moreno, Suhrud M. Rajguru, Agnella I. Matic, Nitin Yerram, Alan M. Robinson, Claus-Peter Richter, Northwestern Univ. (United States)
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It has been demonstrated previously that infrared neural stimulation (INS) can be utilized to stimulate spiral ganglion cells in the cochlea. Although neural stimulation can be achieved without direct contact of the radiation source and the tissue, the presence of fluids or bone between the target structure and the radiation source may lead to absorption or scattering of the radiation. Absorption or scattering of radiation may limit the efficacy of INS. The present study demonstrates that only neural structures in the beam path are stimulated. The histological reconstructions of guinea pig cochleae stimulated with INS suggest that the orientation of the beam from the optical fiber determined the site of stimulation in the cochlea. Best frequencies of the neural responses obtained from the central nucleus of the inferior colliculus matched the histological site in the spiral ganglion. Overall, the results indicated that the stimulated structures in the cochlea are the spiral ganglion cells and not the nerve fibers in the center of the modiolus.

MEMS motor-based common-path endoscopic Fourier-domain OCT

Paper 7893-35 of Conference 7893
Date: Monday, 24 January 2011
Time: 3:20 PM – 3:40 PM

Author(s): Rui Wang, Clemson Univ. (United States); Xiaocong Yuan, Nankai Univ. (China); Bo Li, Clemson Univ. (United States); Richard L. Goodwin, Univ. of South Carolina (United States); Roger R. Markwald, Medical Univ. of South Carolina (United States); Bruce Z. Gao, Clemson Univ. (United States)
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A MEMS motor based common-path Fourier-domain OCT for endoscopic imaging, which uses the interface of index match oil and distal-end surface of the fiber as a self-aligned reference mirror, is reported. The reference intensity is easy to be tuned by altering the index of the match oil to optimize the signal to noise ratio of the system. An external Michelson interferometer is used to compensate for the optical path difference and mismatch of dispersion due to index match oil and GRIN lens. Due to this common-path design, the OCT signal is immune to bending or stretching of the catheter.

MEMS motor-based common-path endoscopic Fourier-domain OCT

Paper 7930-35 of Conference 7930
Date: Monday, 24 January 2011
Time: 3:20 PM – 3:40 PM

Author(s): Rui Wang, Clemson Univ. (United States); Xiaocong Yuan, Nankai Univ. (China); Bo Li, Clemson Univ. (United States); Richard L. Goodwin, Univ. of South Carolina (United States); Roger R. Markwald, Medical Univ. of South Carolina (United States); Bruce Z. Gao, Clemson Univ. (United States)
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A MEMS motor based common-path Fourier-domain OCT for endoscopic imaging, which uses the interface of index match oil and distal-end surface of the fiber as a self-aligned reference mirror, is reported. The reference intensity is easy to be tuned by altering the index of the match oil to optimize the signal to noise ratio of the system. An external Michelson interferometer is used to compensate for the optical path difference and mismatch of dispersion due to index match oil and GRIN lens. Due to this common-path design, the OCT signal is immune to bending or stretching of the catheter.

Optical propulsion of mammalian eukaryotic cells on an integrated channel waveguide

Paper 7929-7 of Conference 7929
Date: Monday, 24 January 2011
Time: 3:20 PM – 3:40 PM

Author(s): Mukhzeer M. Shahimin, Univ. of Southampton (United Kingdom) and Univ. Malaysia Perlis (Malaysia); Nicolas M. Perney, Suzanne Brooks, Univ. of Southampton (United Kingdom); Neil Hanley, The Univ. of Manchester (United Kingdom); Kate L. Wright, James S. Wilkinson, Tracy Melvin, Univ. of Southampton (United Kingdom)
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The optical propulsion of mammalian eukaryotic cells along the surface of an integrated channel waveguide is demonstrated. 10µm diameter polymethylmethacrylate (PMMA) spherical particles and similarly sized mammalian eukaryotic cells in aqueous medium are deposited in a reservoir over a caesium ion-exchanged channel waveguide. Light from a fiber laser at 1064nm was coupled into the waveguide, causing the polymer particles or cells to be propelled along the waveguide at a velocity which is dependent upon the laser power. The results are discussed against theoretical model and in light of the potential application of optical channel waveguides for bioanalytical applications.

Stimulated Raman scattering for chemical-specific analysis of cellular response to thermal insult

Paper 7903-51 of Conference 7903
Date: Monday, 24 January 2011
Time: 5:05 PM – 5:17 PM

Author(s): Hope T. Beier, Air Force Research Lab. (United States); Gary D. Noojin, TASC, Inc. (United States); Benjamin A. Rockwell, Air Force Research Lab. (United States)
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A stimulated Raman scattering microscopy system, based on super-continuum generation from a photonic crystal fiber, has been developed to monitor the cellular mechanisms resulting from thermal insult. Stimulated Raman scattering has been demonstrated to allow label-free, background-free imaging of cells with chemical specificity. The method is used here for rapid spectral detection of protein denaturation, a characteristic of thermal damage, as well as shift-specific imaging of intracellular protein distribution. Cell viability as well as possible protein renaturation is monitored after exposure. These results are compared to previous research on cell death from thermal damage due to laser exposure.

Combined acoustic-photoacoustic and fluorescence imaging catheter for the detection of the atherosclerosis plaque

Paper 7899-95 of Conference 7899
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Maxime Abran, Carl Matteau-Pelletier, Karim Zerouali-Boukhal, Ecole Polytechnique de Montréal (Canada); Jean-Claude Tardif, Montréal Heart Institute (Canada); Frédéric Lesage, Ecole Polytechnique de Montréal (Canada)
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A system combining intravascular ultrasound (IVUS) imaging, intravascular photoacoustic (IVPA) imaging and fluorescence has been developed. The device includes a rotating transducer in a catheter to which an optical fiber is attached. Cylindrical silicon phantoms with inclusions containing fluorophores, ink or gold nanoshells were used to validate the system. IVUS images were obtained continuously and used to co-register photoacoustic and fluorescence signals. The IVPA/IVUS/Fluorescence catheter combination provides a mean to use molecular probe cocktails potentially leading to a better characterization of the structure and composition of the plaque, as well as its vulnerability.

Generation-2 optical-resolution photoacoustic microscopy with improved sensitivity and scanning speed

Paper 7899-112 of Conference 7899
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Konstantin Maslov, Song Hu, Lihong V. Wang, Washington Univ. in St. Louis (United States)
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We develop a second-generation optical-resolution photoacoustic microscopy (OR-PAM) system. Free-space optical delivery in our previously developed OR-PAM (first-generation OR-PAM) was replaced by single-mode fiber optics to enable mechanical scanning of the imaging head. A rhomboid prism was paired with a right-angle prism diagonally, with a thin layer of silicone oil in between, to align the optical irradiation and ultrasonic detection coaxially and confocally. With optical scanning, OR-PAM can image a 100×100 m2 area with video rate. The sensitivity and the imaging speed of the new system were improved by ~18 dB and 3 times, respectively, compared with the 1st-generation OR-PAM.

In-vivo ultra-high-resolution human retinal imaging by dual-channel full-field optical coherence tomography

Paper 7889-105 of Conference 7889
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Masahiro Akiba, Topcon Corp. (United States); Charles Reisman, Zhenguo Wang, Yasufumi Fukuma, Kinpui Chan, Topcon Medical Systems, Inc. (United States)
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Full-field optical coherence tomography (FF-OCT) capable of non-scanning horizontal cross-sectional imaging has been demonstrated for cellular-level human retinal imaging in vivo. The system is based on an interference microscope illuminated by a broadband light source. A dual-channel two-dimensional detection technique incorporated with a pair of CCD cameras has been employed, where a pair of interferometric images with a phase shift of pi are simultaneously captured. To reduce a fringe washout, a short duration illumination technique has been applied. Human retinal nerve fiber bundles and cone mosaic were clearly observed by ultrahigh resolution FF-OCT.

Laser welding of chitosan-GNRs films for the closure of a capsulorhexis

Paper 7885-58 of Conference 7885
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Francesca Rossi, Paolo Matteini, Fulvio Ratto, Istituto di Fisica Applicata Nello Carrara (Italy); Luca Menabuoni M.D., Ivo Lenzetti, Azienda USL 4 (Italy); Roberto Pini, Istituto di Fisica Applicata Nello Carrara (Italy)
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In this work we present the first attempt to close the anterior lens capsule bag by the use of chitosan patches were Gold NanoRods are embedded. The chitosan-GNRs films are used as a novel nanocomposite for the photothermal conversion of NIR light during laser welding. A capsulorhexis was performed in porcine eyes; the patch was put onto the capsule bag and welded: a diode laser (810 nm) was used to deliver single spots (200 m core diameter optical fiber) of local capsule/patch adhesion. The result is an immediate closure of the capsular tissue, with high mechanical strength.

Speckle-correlation monitoring of the internal microvascular flow

Paper 7898-48 of Conference 7898
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Pavel Novikov, Dmitry A. Zimnyakov, Roman A. Zdrajevsky, Valery V. Tuchin, Maxim Vilensky, N.G. Chernyshevsky Saratov State Univ. (Russian Federation)
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EXPERIMENT Speckle -correlation monitoring of the variations in the micro-hemodynamics in the surface layers of different organs of laboratory animals (rats) under the influence of different factors (short-term blocking of microcirculation via the clipping of blood vessels with the subsequent restoration of microcirculation level; the artificial provocation of peritonitis; of the injection of the vasodilating agents, which cause making more active or suppression of hemodynamics) it was produced with the aid of the laboratory model of the speckle-correlometer of the full field with the multichannel fiber-optic to transfer of speckle- modulated scattered radiation to the detector. EXPERIMENTAL RESULTS As a result of experiments we have seen direct dependence of increase of contrast on reduction of linear speed of scatterers of a surface of object.

Efficient deep-UV generation from sub-μJ 30 fs-pulses in Ar-filled hollow-core photonic crystal fibre

Paper 7914-22 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 8:30 AM – 9:00 AM

Author(s): Nicolas Y. Joly, Max-Planck-Institut für die Physik des Lichts (Germany) and Friedrich-Alexander-Univ. Erlangen-Nürnberg (Germany); Philipp Hoelzer, Max-Planck-Institut für die Physik des Lichts (Germany); Johannes Nold, Friedrich-Alexander-Univ. Erlangen-Nürnberg (Germany); Wonkeun Chang, Gordon Wong, Alexander Nazarkin, Philipp J. Russell, Max-Planck-Institut für die Physik des Lichts (Germany)
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Hollow-core photonic crystal fiber (PCF) offers an unprecedented diffractionless system, where the interactions between guided light and the material filling the core are greatly enhanced. We report recent experimental advances in the interaction between fs-pulses and noble-gases in PCF, with particular focus on efficient generation of UV. Two processes are presented: phase-matching to higher-order modes, and growth of dispersive waves in the UV region. In the latter case, tunable deep UV (200-320nm) light is generated with efficiencies as high as 4%, using 35 fs sub-μJ pulses at 800 nm. Most significant is that the UV remains in the fundamental mode.

Polarization-sensitive optical coherence tomography imaging at 1300 nm using a Fourier-domain mode locked laser

Paper 7889-32 of Conference 7889
Date: Tuesday, 25 January 2011
Time: 9:15 AM – 9:30 AM

Author(s): Marco Bonesi, Michael Pircher, Erich Götzinger, Stefan Zotter, Teresa Torzicky, Medizinische Univ. Wien (Austria); Christoph M. Eigenwillig, Benjamin R. Biedermann, Wolfgang Wieser, Robert A. Huber, Ludwig-Maximilians-Univ. München (Germany); Christoph K. Hitzenberger, Medizinische Univ. Wien (Austria)
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We present a polarization-maintaining fiber-based high resolution Fourier domain polarization sensitive optical coherence tomography (PS-OCT) system based on a Fourier domain mode-locked (FDML) laser source with central wavelength of 1300 nm and tunable sweep range up to 130 nm. The imaging principles are based on sample illumination by circularly polarized light and measuring the arbitrary backreflected elliptical polarization state from the sample. We demonstrate the capability of the system to retrieve reflectivity, retardation and birefringent axis orientation by using only one single input polarization state of the probing radiation. PS-OCT images of human skin (fingertip), fingernail and eye angle chamber in vivo are reported to demonstrate system performance.

Rotation sensing using ring resonators

Paper 7913-40 of Conference 7913
Date: Tuesday, 25 January 2011
Time: 11:20 AM – 11:50 AM

Author(s): Michel J. F. Digonnet, Stanford Univ. (United States)
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In recent years, several configurations of coupled ring resonators have been proposed to detect rotation. Theoretical studies conducted by different research groups have concluded that these structures offer tremendous enhancement in rotation sensitivity over conventional optical gyroscopes. In this presentation, we provide physical and theoretical arguments showing that these conclusions are incorrect. Coupling resonators together does not improve the sensitivity to rotation over a single-ring resonator, such as the classic resonant fiber optic gyroscope (RFOG). This presentation includes a discussion of a relatively new structure, in which distributed instead of local coupling takes place between adjacent resonators

Complete measurement of nanosecond laser pulses in time made simple

Paper 7914-38 of Conference 7914
Date: Tuesday, 25 January 2011
Time: 12:00 PM – 12:20 PM

Author(s): Rick P. Trebino, Georgia Institute of Technology (United States); Pamela R. Bowlan, Swamp Optics, LLC (United States)
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It is relatively straightforward to completely measure both long (>10ns) and short (<100ps) laser pulses in time. But intermediate pulse lengths remain challenging. Here we describe a simple, elegant, accurate, complete, compact, all-optical, and single-shot frequency-resolved-optical-gating device that solves the problem. It simultaneously achieves a very large delay range (~10ns) and very high spectral resolution (<1pm) using high-efficiency, high-finesse etalons. The first tilts the pulse by 89.9°-several meters over a centimeter beam, and another generates massive angular dispersion for a high-resolution spectrometer. We use this device to measure pulses 100ps to several ns long from a fiber-amplified micro-disk laser.

Integrated en-face optical coherence endomicroscopy and two-photon fluorescence endomicroscopy for simultaneous multimodal imaging

Paper 7889-42 of Conference 7889
Date: Tuesday, 25 January 2011
Time: 1:45 PM – 2:00 PM

Author(s): Jiefeng Xi, Yuying Zhang, Li Huo, Yong-Ping Chen, Xingde Li, The Johns Hopkins Univ. (United States)
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A 1310-nm optical coherence endomicroscopy (OCEM) system and an 800-nm two-photon fluorescence endomicroscopy system were combined into one single configuration. A dichroic mirror was used to make the two wavelength lights share the same path. Both imaging modalities shared the same miniature imaging probe consisting of a DCF, a PZT scanner and a compound lens, suitable for simultaneous acquisition of en face OCEM and TPF images. The core of the DCF delivered 800 nm excitation light for TPF and 1310 nm light for OCEM while the inner cladding of DCF collected the TPF signal. Two-dimensional beam scanning was realized by resonantly scanning a fiber-optic cantilever with a PZT. We obtained en face OCEM images with axial and lateral resolutions of 9.6 µm in tissue and 1.8 µm, respectively, co-registered with TPF images with axial and lateral resolutions of 7.6 and 1.4 µm, respectively. Preliminary results show promising capability of providing simultaneous structural and molecular images.

Handheld video-rate fluorescence diffuse optical tomography for mapping sentinel lymph nodes

Paper 7896-51 of Conference 7896
Date: Tuesday, 25 January 2011
Time: 1:50 PM – 2:10 PM

Author(s): Metasebya Solomon, Brian R. White, Ralph E. Nothdurft, Walter J. Akers, Adam T. Eggebrecht, Samuel Achilefu, Joseph P. Culver, Washington Univ. in St. Louis (United States)
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We have developed a fiber-based handheld video-rate fluorescence diffuse optical tomography system for noninvasive in vivo sentinel lymph node (SLN) mapping. Frequency encoded fluorescent emission and reference transmission signals are acquired concurrently to generate ratio-metric data. Accurate depth localization and high sensitivity to fluorescent targets was established in tissue simulating phantoms. We have also confirmed invivo performance by imaging the accumulation of a NIR dye into a lymphnode above the shoulder of a rat after injection into the forepaw. These results suggest that handheld video-rate fluorescent DOT has significant potential as a clinical tool for noninvasive mapping of SLN

Near-infrared optical mammography with broadband spectral imaging and depth discrimination

Paper 7896-52 of Conference 7896
Date: Tuesday, 25 January 2011
Time: 2:10 PM – 2:30 PM

Author(s): Yang Yu, Angelo Sassaroli, Tufts Univ. (United States); Marc J. Homer, Roger A. Graham, Tufts Medical Ctr. (United States); Sergio Fantini, Tufts Univ. (United States)
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We have previously reported the development of an instrument for diffuse spectral imaging of the human breast operating over the wavelength range 650-900 nm. We have now implemented depth discrimination capabilities by introducing two additional collection optical fibers that are off-axis in the x and y directions, respectively, with respect to the illumination optical fiber. Validation of the new depth discrimination capabilities has been performed on tissue-like phantoms. We report depth resolved images of healthy human breasts and initial clinical results on cancer-bearing breasts that show the potential of our spectral oxygenation imaging approach combined with depth discrimination.

Ultrasound guided 3D-OCT imaging in deep tissue with a rotating needle probe

Paper 7890-38 of Conference 7890
Date: Tuesday, 25 January 2011
Time: 2:15 PM – 2:30 PM

Author(s): Andrea Curatolo, Bryden C. Quirk, Robert A. McLaughlin, David D. Sampson, The Univ. of Western Australia (Australia)
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We developed a side-facing OCT needle probe capable of acquiring 3D data volumes. Focusing optics consist of no-core and graded-index fiber. The probe is mechanically rotated and retracted to obtain a 3D-OCT dataset. Unfortunately, such OCT needle probes have a small field of view, making it difficult to locate the tissue to be imaged. Ultrasound guidance of biopsy needles is commonly used in clinical settings. We describe an experimental setup where the ultrasound probe is used to provide real-time guidance for OCT needle placement, and visualize tissue structures in both OCT and ultrasound. The technique is demonstrated on tissue phantoms.

Single-carrier versus sub-carrier bandwidth considerations for coherent optical systems

Paper 7959-5 of Conference 7959
Date: Tuesday, 25 January 2011
Time: 3:50 PM – 4:20 PM

Author(s): John D. McNicol, Infinera Canada (Canada); Vinayak Dangui, Infinera Corp. (United States); Han Sun, David J. Krause, Kuang-Tsan Wu, Infinera Canada (Canada); Matthew L. Mitchell, David F. Welch, Infinera Corp. (United States)
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Recently, 40 and 100 Gb/s Ethernet services have been defined. 400G and 1 Tb/s services can be anticipated in the future. Optical transport networks can enable a separation between the services provided and the underlying optical transport; service bandwidths may be larger or smaller than that carried on a single optical 'wave'. In this work, we compare and contrast different arrangements for optical transport of systems having spectral efficiencies in the range of 2 - 5 bits/sec/Hz for sub-carrier bandwidths spanning 25 - 100 GHz. The analysis is made more challenging by variables such as fiber type, dispersion compensation arrangement, and traffic mix.

Single-carrier versus sub-carrier bandwidth considerations for coherent optical systems

Paper 7960-5 of Conference 7960
Date: Tuesday, 25 January 2011
Time: 3:50 PM – 4:20 PM

Author(s): John D. McNicol, Infinera Canada (Canada); Vinayak Dangui, Infinera Corp. (United States); Han Sun, David J. Krause, Kuang-Tsan Wu, Infinera Canada (Canada); Matthew L. Mitchell, David F. Welch, Infinera Corp. (United States)
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Recently, 40 and 100 Gb/s Ethernet services have been defined. 400G and 1 Tb/s services can be anticipated in the future. Optical transport networks can enable a separation between the services provided and the underlying optical transport; service bandwidths may be larger or smaller than that carried on a single optical 'wave'. In this work, we compare and contrast different arrangements for optical transport of systems having spectral efficiencies in the range of 2 - 5 bits/sec/Hz for sub-carrier bandwidths spanning 25 - 100 GHz. The analysis is made more challenging by variables such as fiber type, dispersion compensation arrangement, and traffic mix.

A tunable diode laser absorption system for long path atmospheric transmission and high energy laser applications

Paper 7924-19 of Conference 7924
Date: Tuesday, 25 January 2011
Time: 4:20 PM – 4:40 PM

Author(s): Glen P. Perram, Christopher A. Rice, Air Force Institute of Technology (United States)
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An open-path Tunable Diode Laser Absorption (TDLAS) system composed of narrow band diodes fiber coupled to a 12" Ritchey-Chrétien transmit telescope has been developed to study atmospheric transmission of key High Energy Laser wavelengths. The ruggedized system has been field deployed and tested for propagation distances of exceeding 1 km in the vicinity of the potassium Diode Pumped Alkali Laser wavelength and the oxygen X3Σg - b1Σg+ electronic transition lines near 760 nm. By comparing the TDLAS spectra with a non-imaging FTIR absorption spectra at 1 cm-1, validation of a method for monocular passive ranging is also achieved.


First in-vivo spectral characterization of breast up to 1300 nm

Paper 7896-57 of Conference 7896
Date: Tuesday, 25 January 2011
Time: 4:20 PM – 4:40 PM

Author(s): Paola Taroni, Ilaria Bargigia, Andrea Farina, Rinaldo Cubeddu, Antonio Pifferi, Politecnico di Milano (Italy)
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In vivo spectral measurements of breast were performed for the first time from 600 to 1300 nm using a system for time domain spectroscopy. The set-up relies on a spectrally selected supercontinuum fiber source, a single photon avalanche photodiode (600-1100 nm) and a PMT with InP/InGaAsP photocathode (900-1300 nm). In vivo measurements revealed the potential interest of the 1000-1300 nm range. The attenuation is low enough for in vivo spectroscopy over the entire range. Minor absorption features are present. A dominant peak around 1200 nm might cause exceeding attenuation; still it represents a strongly characterizing feature. Lipid and collagen were also characterized up to 1300 nm.

Generation of watt level mid-infrared wavelengths using intracavity ZnGeP2 OPO within a 2.1μm Ho:YAG laser

Paper 7917-23 of Conference 7917
Date: Tuesday, 25 January 2011
Time: 4:40 PM – 5:00 PM

Author(s): Lihao Tan, Nanyang Technological Univ. (Singapore) and DSO National Labs. (Singapore); Poh Boon Phua, DSO National Labs. (Singapore) and Nanyang Technological Univ. (Singapore)
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We would like to report on watt level mid-infrared (MIR) wavelength generation using intracavity ZnGeP_2 (ZGP) optical parametrical oscillator (OPO) within a 2.1µm Ho:YAG Laser. With the same laser setup, watt level of both 2.1µm and MIR wavelengths were generated concurrently. An average output power of >10W of 2.1µm and >1W of MIR wavelength at 5KHz repetition rate were achieved from a 36W Tm Fiber pump laser. Optimizing the output coupling of the Ho:YAG laser achieve 12W of 2.1µm wavelength. A preliminary result of the intracavity ZGP OPO generates >1W of MIR wavelength.

High temperature multiparameter sensor with 1000°C capability

Paper 7934-13 of Conference 7934
Date: Tuesday, 25 January 2011
Time: 4:40 PM – 5:00 PM

Author(s): Robert B. Walker, Dan Grobnic, Stephen J. Mihailov, Communications Research Ctr. Canada (Canada)
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Spectral characteristics of fiber Bragg gratings are affected by both strain and temperature. While this makes gratings useful for sensing, care must be taken to ensure adequate discrimination between spectral shifts associated with strain and those due to changes in temperature. Recently, monitoring of tilted grating cladding modes has been utilized for this purpose. The drawback of presently published examples is that none offer such measurement capabilities at high temperature (800 ~ 1000 °C). In this paper, by exploiting the characteristics of Type II fs-IR written gratings, we present such an example. Achieving similar responsivity with significantly improved thermal durability.

Hyper coherent linewidth control for a 30mW 405nm visible laser diode by delayed self-heterodyne beat

Paper 7913-47 of Conference 7913
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Masahiro Matsumura, Toshiki Kuromori, Wakao Sasaki, Doshisha Univ. (Japan)
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We have demonstrated a hyper coherent spectral linewidth evaluation for a frequency stabilized 30mW, 405nm GaN violet laser diode (LD) based on the delayed self-heterodyne beat. The LD was stabilized to a CFP cavity by an electrical optical double feedback method. In this scheme, 1.65X10^-11 stability estimated with Allan variance was achieved. In this work, we have further measured our narrowed linewidth by the delayed self heterodyne technique which consists of optical fiber of about 30km length. As a result, the reduced linewidth under the double feedback conditions has been estimated to be narrower than at least several hundreds kHz, to be the resolution limit of our measurement.

Study on the 1123 nm continuous-wave ceramic Nd:YAG laser

Paper 7912-67 of Conference 7912
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Sasa Zhang, Qingpu Wang, Xingyu Zhang, Zhaojun Liu, Aiqun Long, Shandong Univ. (China)
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Highly efficient 1123 nm continuous-wave lasers are realized with ceramic Nd:YAG materials. A fiber-coupled continuous-wave 808-nm diode laser is used as the pumping source. Two ceramic Nd:YAG rods with the same length of 10 mm and different Nd-doping concentrations are employed during our experiments. With the same incident diode power of 26.1 W, a cw output power of up to 10.8 W is obtained with the 1.0 at. %-Nd-doped rod, while 8.2 W output power is generated from the 0.6 at. %-Nd-doped rod. The highest conversion efficiency from diode power to 1123-nm laser power is 43.8% and 31.4%, respectively, for the two Nd:YAG rods.

Enabling technologies for 100G coherent optical communication

Paper 7958-8 of Conference 7958
Date: Wednesday, 26 January 2011
Time: 8:30 AM – 9:00 AM

Author(s): Bo Zhang, Yannick K. Lize, Opnext, Inc. (United States)
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In this paper, we review the generation, detection and long-haul transmission of single-wavelength coherent PM-QPSK systems. The enabling technology of the 100G coherent transponder is first described from the systems attributes. Lab results then follow from various fiber-channel degrading effects, including cascading of more than ten 50GHz ROADMs over 1500km transmission testbed. We conclude with a recent field trial of upgrading an installed 10-Gb/s field system to 100-Gb/s using an FPGA-based real-time, single-carrier, coherent transponder prototype. Transmission over installed 1800km link was achieved with sufficient performance for error-free operation after FEC.

Enabling technologies for 100G coherent optical communication

Paper 7959-8 of Conference 7959
Date: Wednesday, 26 January 2011
Time: 8:30 AM – 9:00 AM

Author(s): Bo Zhang, Yannick K. Lize, Opnext, Inc. (United States)
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In this paper, we review the generation, detection and long-haul transmission of single-wavelength coherent PM-QPSK systems. The enabling technology of the 100G coherent transponder is first described from the systems attributes. Lab results then follow from various fiber-channel degrading effects, including cascading of more than ten 50GHz ROADMs over 1500km transmission testbed. We conclude with a recent field trial of upgrading an installed 10-Gb/s field system to 100-Gb/s using an FPGA-based real-time, single-carrier, coherent transponder prototype. Transmission over installed 1800km link was achieved with sufficient performance for error-free operation after FEC.

Enabling technologies for 100G coherent optical communication

Paper 7960-8 of Conference 7960
Date: Wednesday, 26 January 2011
Time: 8:30 AM – 9:00 AM

Author(s): Bo Zhang, Yannick K. Lize, Opnext, Inc. (United States)
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In this paper, we review the generation, detection and long-haul transmission of single-wavelength coherent PM-QPSK systems. The enabling technology of the 100G coherent transponder is first described from the systems attributes. Lab results then follow from various fiber-channel degrading effects, including cascading of more than ten 50GHz ROADMs over 1500km transmission testbed. We conclude with a recent field trial of upgrading an installed 10-Gb/s field system to 100-Gb/s using an FPGA-based real-time, single-carrier, coherent transponder prototype. Transmission over installed 1800km link was achieved with sufficient performance for error-free operation after FEC.

Self-organized InAs quantum dot tube lasers and integrated optoelectronics on Si

Paper 7943-47 of Conference 7943
Date: Wednesday, 26 January 2011
Time: 9:50 AM – 10:20 AM

Author(s): Zetian Mi, Pablo Bianucci, Feng Li, Zhaobing Tian, Venkat Veerasubramanian, Andrew G. Kirk, David V. Plant, McGill Univ. (Canada); Philip J. Poole, National Research Council Canada (Canada)
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Self-organized quantum dot tube cavities are formed when a coherently strained quantum dot heterostructure is selectively released from the host substrate. We have demonstrated ultralow threshold (~ 4 µW) 1.3 μm InAs/GaAs quantum dot tube lasers and achieved strong 1.55 µm coherent emission from InAs/InP quantum dot tubes. With the use of substrate-on-substrate and fiber taper assisted transfer processes, such novel nanophotonic devices can be achieved on Si or any other platform. Work is currently in progress to demonstrate electrically injected 1.3 and 1.55 µm self-organized quantum dot tube lasers on Si by employing a novel lateral p-i-n junction design.

Self-organized InAs quantum dot tube lasers and integrated optoelectronics on Si

Paper 7953-47 of Conference 7953
Date: Wednesday, 26 January 2011
Time: 9:50 AM – 10:20 AM

Author(s): Zetian Mi, Pablo Bianucci, Feng Li, Zhaobing Tian, Venkat Veerasubramanian, Andrew G. Kirk, David V. Plant, McGill Univ. (Canada); Philip J. Poole, National Research Council Canada (Canada)
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Self-organized quantum dot tube cavities are formed when a coherently strained quantum dot heterostructure is selectively released from the host substrate. We have demonstrated ultralow threshold (~ 4 µW) 1.3 μm InAs/GaAs quantum dot tube lasers and achieved strong 1.55 µm coherent emission from InAs/InP quantum dot tubes. With the use of substrate-on-substrate and fiber taper assisted transfer processes, such novel nanophotonic devices can be achieved on Si or any other platform. Work is currently in progress to demonstrate electrically injected 1.3 and 1.55 µm self-organized quantum dot tube lasers on Si by employing a novel lateral p-i-n junction design.

Leveraging electric and magnetic dipole transitions for active nanophotonic devices

Paper 7945-74 of Conference 7945
Date: Wednesday, 26 January 2011
Time: 10:40 AM – 11:00 AM

Author(s): Rashid Zia, Brown Univ. (United States)
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In this talk, we will explore the device implications of controlling the strong magnetic dipole transitions in Lanthanide ions (such as the 1550nm line in trivalent Erbium). For decades, Lanthanide ions have served as important light emitters in a range of optical technologies from lighting and displays to solid-state lasers and telecom fiber amplifiers. Recently, our lab has explored a number of optical techniques to selectively enhance both electric and magnetic dipole transitions. In experimental studies, we have demonstrated strong (> 4X) Purcell enhancement of magnetic dipole emission and broad (>100nm) spectral tuning using trivalent Europium. Building on this work, we will discuss new device designs that can be enabled through control of such magnetic transitions. Specifically, we will explain how the differing symmetry of magnetic dipole emitters can open a new degree of design freedom for active nanophotonic devices.

Inactivation of encephalomyocarditis virus and herpes simplex virus by using a visible femtosecond laser

Paper 7895-28 of Conference 7895
Date: Wednesday, 26 January 2011
Time: 12:10 PM – 12:30 PM

Author(s): Shaw-Wei D. Tsen, Washington Univ. in St. Louis (United States); Kong-Thon Tsen, Arizona State Univ. (United States)
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Recently, a variety of viral systems, including M13 bacteriophage, tobacco mosaic virus (TMV), human papillomavirus (HPV) and human immunodeficiency virus (HIV) have been shown to be inactivated by the irradiation of a near-infrared subpicosecond fiber laser. These experimental results indicated that the inactivation of viruses by an ultrashort pulsed laser might involve disruption of their protein coat through laser-induced excitation of large-amplitude acoustic vibrations. In this work, we report experimental results on the inactivation of both encephalomyocarditis virus (EMCV) and herpes simplex virus (HSV) by using a visible femtosecond laser derived from the second harmonic generation of a cw mode-locked Ti-sapphire laser system. The inactivation of these viral particles has been demonstrated to depend on the laser exposure time as well as laser power density. Possible mechanisms for the inactivation will be discussed.

Can a one-layer optical skin model including melanin and inhomogeneously distributed blood explain spatially resolved diffuse reflectance spectra?

Paper 7896-70 of Conference 7896
Date: Wednesday, 26 January 2011
Time: 1:30 PM – 1:50 PM

Author(s): Hanna Karlsson, Linköping Univ. (Sweden); Anders Pettersson, Perimed AB (Sweden); Marcus Larsson, Tomas Strömberg, Linköping Univ. (Sweden)
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Model based analysis of calibrated diffuse reflectance spectroscopy can be used for determining oxygenation and concentration of skin chromophores. This study aimed to assess the effect of including melanin and inhomogeneously distributed blood in a single-layer model. Spectra from four humans were collected during different provocations using a two-channel fiber optic probe with source-detector separation 0.4 and 1.2 mm. Absolute calibrated spectra was analyzed using inverse Monte Carlo and Levenberg-Marquardt techniques. The model was found to fully explain spectra using a single-distance recording. However, it fails to explain multi-distance recordings which suggests that a multi-layered skin model is needed.

An approach for Megahertz OCT: streak mode Fourier-domain optical coherence tomography

Paper 7889-71 of Conference 7889
Date: Wednesday, 26 January 2011
Time: 2:00 PM – 2:15 PM

Author(s): Rui Wang, Clemson Univ. (United States); Xiaocong Yuan, Nankai Univ. (China); Richard L. Goodwin, Univ. of South Carolina (United States); Roger R. Markwald, Medical Univ. of South Carolina (United States); Bruce Z. Gao, Clemson Univ. (United States)
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Currently, area-scan camera can achieve higher data acquisition rate than line-scan camera can. We report a technique, which uses an area-scan camera instead of a line-scan camera to record the interference spectrum. Unlike in other area scan camera based parallel OCT, traditional point-scanning is remained so that the small aperture of the single-mode fiber functions as a confocal gate and screens multiply scattered photons. The interference spectrum is physically scanned on the area scan camera using a streak scanner. Preliminary data was obtained and compared with imaging result from a traditional FD-OCT. This technique is highly potential for multi-Megahertz OCT imaging.

Comparison of 8 Tb/s optical transport systems using different modulation formats

Paper 7960-16 of Conference 7960
Date: Wednesday, 26 January 2011
Time: 2:00 PM – 2:20 PM

Author(s): Han Sun, Infinera Canada (Canada); Vinayak Dangui, Infinera Corp. (United States); David J. Krause, Infinera Canada (Canada); Matthew L. Mitchell, Infinera Corp. (United States); Kuang-Tsan Wu, Infinera Canada (Canada); David F. Welch, Infinera Corp. (United States)
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We compare and contrast the performance of an 8 Tb/s optical transport system using various modulation formats, including variants of a PM-QPSK modulation with equal FEC performance for each scenario. For the same total 8 Tb/s capacity in the C band, we analyze the several approaches from the point of view of: (a) WDM Kerr nonlinear impairments over SMF and LEAF, (b) electronic requirements and complexities, (c) ASIC complexities and heat, and (d) laser line width requirements. We find differences in the approach results in substantially different tolerances in launch power (integrated over the C band) for both SMF and LEAF fiber resulting in varied reach performance. Further scenarios including mixed traffic with 10 Gb/s signals are analyzed and will be presented.

Architecture, design, and numerical simulation of a code/pulse-position-swapping (CPPS) direct translating receiver

Paper 7923-6 of Conference 7923
Date: Wednesday, 26 January 2011
Time: 4:30 PM – 5:00 PM

Author(s): Antonio J. Mendez, Mendez R&D Associates (United States); Vincent J. Hernandez, Corey V. Bennett, Lawrence Livermore National Lab. (United States); Robert M. Gagliardi, The Univ. of Southern California (United States)
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Code/pulse-position-swapping (CPPS) is a communications scheme that translates pulse-position-modulation (PPM) symbols into optical-code-division-access (O-CDMA) codes. CPPS retains the multiple bits per symbol modulation format of PPM and the asynchronous multiple access of O-CDMA. Additionally, CPPS has the advantages of granular communications, common electrical bandwidth for all users independent of data (symbol) rates, compatibility with free-space or guided (fiber and waveguide) communication links, and compatibility with intensity modulation/direct detection. This paper describes the architecture and design of the receiver, based on map-coding. Numerical simulations are used to characterize the receiver concept in terms of symbol and bit error rates.

Cr:ZnSe planar waveguide mid-IR laser

Paper 7912-54 of Conference 7912
Date: Wednesday, 26 January 2011
Time: 4:40 PM – 5:00 PM

Author(s): Jonathan E. Willimas, Dmitri V. Martyshkin, Vladimir V. Fedorov, The Univ. of Alabama at Birmingham (United States); Igor S. Moskalev, IPG Photonics - Mid-Infrared Lasers (United States); Renato P. Camata, Sergey B. Mirov, The Univ. of Alabama at Birmingham (United States)
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We report the first mid-IR Cr:ZnSe planar waveguides lasing and application of the Cr:ZnSe thin-film structures for passive Q-switching of the solid state lasers. The lasing of the Cr:ZnSe waveguide was achieved at 2.6 µm under optical pulse excitation at 1.56 µm. The laser threshold was equal to 100 mJ/cm^2. Highly doped Cr:ZnSe/sapphire sample was used for passive Q-switching of the fiber pumped Er(0.5%):YAG laser operating at 1645 nm. Passively Q-switched Er:YAG laser operated at repetition rate of 20 kHz with an output power of 100 mW and the ratio of the Q-switched to free-running output power of 67%.

Photonic sensors for explosive detection

Paper 7945-87 of Conference 7945
Date: Wednesday, 26 January 2011
Time: 4:50 PM – 5:10 PM

Author(s): Ulrike Willer, Clausthal Univ. of Technology (Germany); Rozalia Orghici, Peter Lützow, Fraunhofer-Institut für Nachrichtentechnik Heinrich-Hertz-Institut (Germany); Wolfgang Schade, Technische Univ. Clausthal (Germany) and Fraunhofer-Institut für Nachrichtentechnik Heinrich-Hertz-Institut (Germany)
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Photonic sensors for the detection of explosives applying photoacoustics and evanescent field spectroscopy combined with silicon photonics and nano-dimensioned waveguides reveal entirely new possibilities for in-situ and real-time diagnostics. Specially engineered receptor films accumulate selectively TNT molecules which are detected very sensitively by evanescent field effects. A second photonic sensor is developed applying photoacoustic spectroscopy (QEPAS). Miniaturized laser technology in combination with silicon photonics and fiber optics enables engineering a smart handheld sensor, e.g. for the detection of TATP (tri-acetone tri-peroxide). Impulsive femtosecond laser excitation as new approach for selective multi-species excitation in combination with photoacoustic spectroscopy is also discussed.

Mode-locking of a Cr:ZnSe laser by use of a PPLN nonlinear mirror

Paper 7912-56 of Conference 7912
Date: Wednesday, 26 January 2011
Time: 5:20 PM – 5:40 PM

Author(s): Jean-Baptiste Dherbecourt, Antoine Godard, Adrien Denoeud, Jean-Michel Melkonian, Myriam Raybaut, Michel Lefebvre, Emmanuel Rosencher, ONERA (France)
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We report on the first experimental demonstration of the passive mode-locking of a Cr:ZnSe laser by a tunable PPLN-based nonlinear mirror. The Cr:ZnSe (lambda ≈ 2.5 µm) laser is pumped by a CW thulium-doped fiber laser. An intracavity second-harmonic generator based on a PPLN crystal coupled with a dichroïc mirror (highly reflective at the second harmonic and partially reflective at the fundamental wave) and a dispersive YAG wedged plate is used as an amplitude modulator to achieve mode-locked operation. During this presentation we will discuss the role played by each nonlinear mirror component and their influence on the laser's dynamics.

Nonlinear optical effects-induced spectral broadening in ZnO channel waveguides

Paper 7940-48 of Conference 7940
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Edgar Yoshio Morales Teraoka, Tomohiro Kita, Tohoku Univ. (Japan); Daniel H. Broaddus, Cornell Univ. (United States); Atsushi Tsukazaki, The Univ. of Tokyo (Japan) and PRESTO, Japan Science and Technology Agency (Japan); Masashi Kawasaki, Tohoku Univ. (Japan) and WPI Advanced Institute for Materials Research, Tohoku Univ. (Japan); Alexander L. Gaeta, Cornell Univ. (United States); Hirohito Yamada, Tohoku Univ. (Japan)
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We report the observation of enhanced nonlinear optical effects in ZnO channel waveguides. Our research is focused on obtaining waveguides with enhanced nonlinear properties. We demonstrate spectral broadening using femtosecond optical pulses at a wavelength of 840 nm. We obtained a maximum of six-fold broadening. Spectral features characteristic of SPM were appreciated. We calculated the nonlinear parameter gamma, obtaining values up to 13.9 W-1m-1. It represents more than 1300 times the gamma of a highly nonlinear fiber. Single-crystal ZnO showed to be a promising material for optical waveguides intended for nonlinear applications.

Waveguide integrated plasmonic platform for sensing and spectroscopy

Paper 7941-44 of Conference 7941
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Fatih Degirmenci, Irfan Bulu, Harvard Univ. (United States); Parag Deotare, Mughees Khan, Harvard School of Engineering and Applied Sciences (United States); Marko Loncar, Federico Capasso, Harvard Univ. (United States)
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We propose a waveguide integrated plasmonic platform in order to deliver excitation power to and collect signal efficiently from a nano-antenna. The system consists of a silicon waveguide with an integrated nano-antenna and a fiber spot size converter. The nano-antenna is designed to have a broad resonance around 1.5 microns with an estimated surface enhanced Raman scattering (SERS) enhancement of 7 orders of magnitude and collection efficiency up to 80%. The device was fabricated on a silicon-on-insulator wafer. The proposed and fabricated device can be used in applications involving on-chip SERS spectroscopy and single photon sources with high out-coupling efficiency.

Development of an enhanced adaptive optics system for the Lick Observatory Shane 3-meter telescope

Paper 7931-2 of Conference 7931
Date: Thursday, 27 January 2011
Time: 8:30 AM – 8:55 AM

Author(s): Donald T. Gavel, Univ. of California Observatories (United States)
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We present our plans for a second-generation laser guide star adaptive optics system for the 3-meter Shane Telescope at Lick Observatory. The Shane hosted the first groundbreaking experiments in sodium laser guidestar adaptive optics, with observations starting in 1996, and provides for regular astronomical science observing to this day. The replacement new generation system will incorporate many of the recent advancements in AO technology and lessons learned from laboratory and on-sky experiments in order to provide higher Strehl, higher sensitivity, and greater wavelength coverage for astronomers. The proposed system uses a 32x32 actuator MEMS deformable mirror, along with higher sensitivity wavefront sensor, and a new fiber laser developed at Lawrence Livermore National Laboratory. Our experiences from the Villages project, reported at earlier Photonics West meetings, provide much of the basis for the new system design.

Mid-IR spectral comb with broad instantaneous bandwidth using subharmonic OPO

Paper 7917-43 of Conference 7917
Date: Thursday, 27 January 2011
Time: 8:30 AM – 8:50 AM

Author(s): Nicholas C. Leindecker, Alireza Marandi, Robert L. Byer, Konstantin L. Vodopyanov, Stanford Univ. (United States)
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We implement a new approach for generating broadband mid-infrared frequency combs via degenerate optical parametric oscillation. This technique efficiently transfers the desirable properties of shorter wavelength mode-locked sources to the mid-IR. Thin ( < 1mm) crystals of MgO:PPLN provide broad parametric gain around 3.1-micron subharmonic when synchronously pumped by a 1560nm fiber laser (Menlo Systems, 70 fs, 350 mW). Broadband oscillation occurs when signal/idler are brought into resonance by piezo-tuning the cavity length. An 8% reflective pellicle outcouples up to 60mW in a 1000nm bandwidth centered around 3.1 microns. OPO threshold was measured to be < 35mW. With proper intracavity dispersion management including chirped mirrors, we expect to extend the spectral width to an octave or more.

Compact laser transmitter providing precision aligned visible and infrared beams

Paper 7923-13 of Conference 7923
Date: Thursday, 27 January 2011
Time: 9:00 AM – 9:20 AM

Author(s): Hong-Shik Lee, Yeo-Taek Yoon, Chang-Hyun Park, Haeng-In Kim, Kwangwoon Univ. (Korea, Republic of); Seung-Chan Lim, Korea Telecom (Korea, Republic of); Sang-Shin Lee, Kwangwoon Univ. (Korea, Republic of)
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The free space optics has received enormous attention in view of its variosu applications such as the visible light communications and especially the multiple integrated laser engagement systems (MILES). We have proposed and built a laser transmitter providing precision aligned visible and infrared beams, exploiting an optical sub-assembly module. Both visible (~650 nm) and infrared (~904 nm) laser diodes were combined by a wavelength division multiplexing filter and coupled to a short fiber. They were subsequentl collimated simultaneously to provide two collinear beams. The alignment angle between the visible and infrared beam was <0.01o; the propagation characteristics of the visible and infrared beams were evaluated.

Mid-infrared femtosecond frequency combs for sensing and optical clocks

Paper 7917-45 of Conference 7917
Date: Thursday, 27 January 2011
Time: 9:20 AM – 9:50 AM

Author(s): Irina T. Sorokina, Norwegian Univ. of Science and Technology (Norway); Evgeni Sorokin, Vienna Univ. of Technology (Austria)
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We review recent advances in frequency comb sources based on Cr2+:chalcogenide lasers, operating between 1.9 and 3.6 micron, and their applications to "frequency comb spectroscopy" and other sensing techniques. These lasers exhibit the broadest among existing lasers continuous tuning over 1400 nm and 80-fs pulses, all at ambient conditions. The lasers operate in transportable hybrid fiber-bulk form, and allow novel techniques like dual-comb method and intracavity spectroscopy. The femtosecond frequency combs also serve as a starting point for synchroniously pumped OPOs. The talk highlights the radical efficiency increase when such sources are applied to high-resolution molecular spectroscopy and gas sensing.

Research of diode-pumped cryogenic Yb:YAG amplification at 10 Hz repetition rate

Paper 7916-21 of Conference 7916
Date: Thursday, 27 January 2011
Time: 9:50 AM – 10:10 AM

Author(s): Jiangfeng Wang, Youen Jiang, Xuechun Li, Xiang Li, Shanghai Institute of Optics and Fine Mechanics (China)
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A 1 Joule pulse energy laser system with 10 Hz repetition rate has been developing, which consists of three major components: an all fiber based master oscillator, a diode-pumped cryogenic Yb:YAG regenerative amplifier and a power amplifier with cryogenic Yb:YAG ceramics. A ~100 pJ optical pulse with 10 ns time duration and 10 Hz repetition rate at 1030 nm wavelength is produced by the master oscillator. Then, the optical pulse is injected into the regenerative amplifier and the power amplifier. ~10.5 mJ output energy at 10 Hz from the regenerative amplifier with a square-pulse distortion of ~1.5 was achieved. The gain spectrum dependence on Yb:YAG ceramic temperature was also investigated.

Towards efficient nanophotonic coupling to NV centers

Paper 7948-40 of Conference 7948
Date: Thursday, 27 January 2011
Time: 9:50 AM – 10:10 AM

Author(s): Paul E. Barclay, Univ. of Calgary (Canada); Kai-Mei C. Fu, Charles M. Santori, Andrei Faraon, Raymond G. Beausoleil, Hewlett-Packard Labs. (United States)
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The nitrogen-vacancy (NV) center impurity in diamond possesses well defined optical transitions and optically addressable electronic spins with long coherence times. These properties make the NV center a promising system for quantum information processing and magnetometry. Integrating NV centers with nanophotonic devices would improve the efficiency of NV optical readout and control, and enable scalable optical coupling between multiple NVs. In this presentation we review our recent progress in diamond-based nanophotonics, and present recent experiments using hybrid GaP-diamond microcavities at liquid He temperature, in combination with fiber tapers, to improve collection efficiency of NV photoluminescence.

The dynamics of optoelectronic oscillators

Paper 7933-57 of Conference 7933
Date: Thursday, 27 January 2011
Time: 10:50 AM – 11:20 AM

Author(s): Thomas Erneux, Univ. Libre de Bruxelles (Belgium); Laurent Larger, Univ. de Franche-Comté (France)
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In recent years, compact optoelectronic oscillators (OEOs) have been developed that rival the best RF oscillators over broad offset frequencies. They incorporate an electro-optic modulator, an optical-fiber delay line, and optical detection in a closed-loop resonating configuration. This hybrid source generates an ultra-low-jitter stream of short optical pulses with high repetition-rate capabilities. Today, OEOs have attracted the attention of several laboratories with quite different objectives. They range from fundamental questions ( synchronization properties of two coupled OEOs) to applied projects (chaotic encryption for secure communication). In this presentation, we highlight some of these problems and analyze their mathematical models both numerically and analytically.

Influence of the alfa factor in a nonlinear semiconductor optical amplifier loop mirror performance for pulse shaping of Gain switching diode lasers

Paper 7933-60 of Conference 7933
Date: Thursday, 27 January 2011
Time: 12:00 PM – 12:20 PM

Author(s): Cristina de Dios Fernandez, Horacio Lamela, Univ. Carlos III de Madrid (Spain)
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Experimental and numerical studies are presented where the influence and importance of the dynamic of the Semiconductor Amplifier on the overall pulse compression performance of a Nonlinear Optical Loop Mirror based on an untrafast Semiconductor Optical Amplifier and a highly nonlinear microstructured optical fiber is explored. Results show that the saturation and gain compression are important to understand the system behavior. Along with these effects, the influence of the alpha factor and its dependence on the carrier density under high input conditions is evaluated. Numerical and experimental results show relevant agreement, what sheds light on the device behavior and helps understand the influence of the several physical effects behind it.

Non-adiabatic pulse compression using cascaded higher-order solitons

Paper 7914-58 of Conference 7914
Date: Thursday, 27 January 2011
Time: 12:00 PM – 12:20 PM

Author(s): Jose Nathan Kutz, Univ. of Washington (United States); Qian Li, Hong Kong Polytechnic Univ. (United States); Alex P. K. A. Wai, Hong Kong Polytechnic Univ. (Hong Kong, China)
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Non-adiabatic pulse compression of cascaded higher-order optical soliton is investigated. We demonstrate the high degree compression of pulses with soliton order N=2, 3, 4 and 5 in two or three nonlinear fibers with different second-order dispersion coefficients. Each fiber length is shorter than half of its soliton period. This compression technique has significant advantages over the widely reported adiabatic and higher-order soliton compression. The two-stage or three-stage higher-order soliton compression can greatly increase the compression factor and lower the required input peak power without incurring significant pulse-quality degradation.

Electromagnetic crystal (EMXT) based THz components

Paper 7938-16 of Conference 7938
Date: Thursday, 27 January 2011
Time: 4:00 PM – 4:20 PM

Author(s): Ziran Wu, Wei-Ren Ng, Michael E. Gehm, Hao Xin, The Univ. of Arizona (United States)
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All-dielectric Terahertz waveguides based on hollow-core EMXT fiber are fabricated via THz rapid prototyping using polymer jetting technique. Several waveguides of identical cross-section and differing lengths are characterized by THz time-domain spectroscopy (THz-TDS) to extract the waveguide intrinsic propagation loss. Measurement results agree very well with simulation. This as an initial example demonstrates a waveguide with low propagation loss of 0.03 dB/mm at 105 GHz. Based on the waveguide, an EMXT antenna is also formed by modifying the defect shape into a horn. Simulation shows good performance of this horn antenna. The antenna is fabricated by the same rapid prototyping method, and its far-field pattern measurement result will be reported.

InP on SOI devices for optical communication and optical network on chip

Paper 7942-23 of Conference 7942
Date: Thursday, 27 January 2011
Time: 4:30 PM – 5:00 PM

Author(s): Jean-Marc Fédéli, Badhise Ben Bakir, Lab. d'Electronique de Technologie de l'Information (France)
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For about ten years, we have been developing InP on Si devices. For high performance computing with high speed communication between cores, we developed InP microdisk lasers that are coupled to silicon waveguide and produced 100µW of optical power and that can be directly modulated up to 5G at different wavelengths. The optical network is based on wavelength selective circuits with rings. InGaAs photodetectors are evanescently coupled to the silicon waveguide with an efficiency of 0.8A/W. The fabrication has been demonstrated at 200mm wafer scale in a microelectronics clean room for CMOS compatibility. For off-chip communication, Si on InP evanescent laser have been realized with an innovative design where the cavity is defined in silicon and the gain localized in the QW of bonded InP hererostructure. The investigated devices operate at CW regime with room temperature threshold current below 100 mA, the SMSR is as high as 20dB, and the fiber-coupled output power is ~7mW.

High finesse external cavity VCSELs: from very low noise lasers to dual frequency lasers

Paper 7945-10 of Conference 7945
Date: Sunday, 23 January 2011
Time: 11:00 AM – 11:20 AM

Author(s): Ghaya Baili, Thales Research & Technology (France); Medhi Alouini, Univ. de Rennes 1 (France); Loic Morvan, Thales Research & Technology (France); Fabien Bretenaker, Lab. Aimé Cotton (France); Isabel Sagnes, Ctr. National de la Recherche Scientifique (France); Arnaud Garnache, Univ. Montpellier 2 (France); Daniel Dolfi, Thales Research & Technology (France)
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Low noise-level optical sources are required for numerous applications such as microwave photonics, fiber-optic sensing and time/frequency references distribution. In this paper, we present how inserting a semiconductor active medium into a centimetric high-Q external cavity is a simple way to obtain a shot-noise-limited laser source over a very wide frequency bandwidth. This approach ensures, with a compact design, a sufficiently long photon lifetime to reach the oscillation-relaxation-free class-A regime. This concept has been illustrated by inserting a ½ VCSEL in an external cavity including an etalon filter. A very low relative intensity noise has been observed (-156dB/Hz over the 100 MHz -18 GHz bandwidth) and is at the shot noise limit, thanks to class-A regime operation. The optimization, in terms of noise, is shown to be a trade-off between the cavity length and the laser mode filtering. The transition between the class-B and class-A dynamical behaviors is directly observed by continuously controlling the photon lifetime is a sub-millimetric to a centimetric cavity length. It's proven that the transition occurs progressively, without any discontinuity. Based on the same laser architecture, tunable dual frequency oscillation is demonstrated by reducing the polarized eigenstates overlap in the gain medium. The class-A dynamics of such a laser, free of relaxation oscillations, enables to suppress the electrical phase noise in excess, usually observed in the vicinity of the beat note and thus appears as a laser source of choice to be used in atomic clocks.

Selective nanoparticle-directed photothermal ablation of the canine prostate

Paper 7901-41 of Conference 7901
Date: Monday, 24 January 2011
Time: 4:50 PM – 5:05 PM

Author(s): Jon A. Schwartz, Nanospectra Biosciences, Inc. (United States); Roger E. Price D.V.M., Baylor College of Medicine (United States); Kelly L. Gill-Sharp, Krystina L. Sang, Jennifer D. Khorchani, J. Donald Payne, Nanospectra Biosciences, Inc. (United States); Bradford S. Goodwin, The Univ. of Texas Health Science Ctr. at Houston (United States)
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This study adapted AuroLase® Therapy, previously reported for the treatment of brain tumors, to the treatment of prostate disease by 1) using normal canine prostate in vivo, directly injected with a solution of nanoparticles as a proxy for prostate tumor and, 2) developing an appropriate laser dosimetry for prostate which is which is sub-ablative in native prostate while simultaneously producing photothermal coagulation in prostate tissue containing therapeutic nanoshells. Healthy, mixed-breed hound dogs were given surgical laparotomies during which nanoshells were injected directly into one or both prostate hemispheres. Laser energy was delivered percutaneously to the parenchyma of the prostate along 1-5 longitudinal tracts via a liquid-cooled optical fiber catheter terminated with a 1-cm isotropic diffuser after which the incision was closed and sutured using standard surgical techniques. The photothermal lesions were permitted to resolve for up to 8 days, after which each animal was euthanized, necropsied, and the prostate taken for histopathological analysis. We developed a laser dosimetry which is sub-ablative in native prostate and simultaneously ablative of prostate tissue containing nanoshells which would indicate a viable means of treating tumors of the prostate which are known from other studies to accumulate nanoshells. Secondly, we determined that multiple laser treatments of nanoshell-containing prostate tissue could be accomplished while sparing the urethra and prostate capsule thermal damage. Finally, we determined that the extent of damage zone radii correlate positively with nanoshell concentration, and negatively to the length of time between nanoshell injection and laser treatment.

Advancements in photomixing and photoconductive switching for THz spectroscopy and imaging

Paper 7938-1 of Conference 7938
Date: Thursday, 27 January 2011
Time: 8:00 AM – 8:30 AM

Author(s): Elliott R. Brown, Wright State Univ. (United States) and Physical Domains, LLC (United States)
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Ultrafast photoconductive devices have been an important breakthrough in THz technology during the past two decades. Photoconductive switches have become the workhorse in moderate-resolution time-domain systems, and photomixers have been widely implemented in high-resolution spectrometers of various types. The primary photoconductive material has been low-temperature-grown GaAs. More recently, this has been rivaled by ErAs-GaAs: a nanocomposite consisting of ErAs nanoparticles embedded in a GaAs matrix. ErAs-GaAs photomixers have produced very useful THz output power levels between 1.0 and 10.0 microwatt when pumped by low-cost DFB lasers operating around 780 nm. ErAs-GaAs photoconductive switches have produced average output power approaching 1 mW, and peak power exceeding 1 W when pumped by frequency-doubled fiber model-locked lasers. The photomixer performance has been utilized in the first U.S. commercial THz photomixing spectrometer which has already been demonstrated on a variety of interesting materials including polar vapors, solid explosives, polysaccharides, nucleic acids, and nonlinear-optical crystals. The photoconductive switch performance has been utilized in a THz impulse radar having a broadband power spectrum centered at around 500 GHz, and a relatively simple gated-receiver to provide pulse averaging and noise reduction. The impulse radar has been used for several applications in biomedical imaging, such as imaging of skin burns, skin cancer, and the ocular cornea.

Trimodal spectra for high discrimination of benign and malignant prostate tissue

Paper 7895-35 of Conference 7895
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Mohamad Al Salhi, King Saud Univ. (Saudi Arabia); Vijmasi Trinka, Thendrel Inc (United States); Vadivel Masilamani, Danny Rabah, Mohammed R. Turki, King Saud Univ. (Saudi Arabia)
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Cancer of prostate occurs more frequently for older men and for many of them the malignancy is not aggressive. So a non-invasive technique of spectral scaling of virulence of malignancy is our ultimate goal. The first step is spectral discrimination of benign from malignant tumor. In this paper, we have done fluorescence emission spectrum (FES), Stokes' shift Spectrum (SSS) and reflectance spectrum (RLS) of excised benign and malignant tumor tissues (N = 15 each). The tissues were minced, washed five times and dried before loading into the quartz cuvette for spectral analysis. The FES was done with excitation at 325nm only; SSS with ∆λ = 70, and ∆λ = 0, the latter being equivalent to reflectance spectra. Of the three modes of spectra, SSS with ∆λ =70nm showed the best discrimination. There were four important bands, one at 280nm (due to tryptophan); 320nm (due to elastin & tryptophan); 355 and 385 (due to NADH) and 440nm (due to flavin). From the relative intensities of these bands, three ratios were evaluated. Similarly another two ratios were obtained from reflectance spectra and two more from FES. Thus, there are 7 ratio parameters which represent the relative concentration of tryptophan, elastin, NADH and flavin. A statistical analysis showed that benign and malignant tissues could be classified with accuracy greater than 90%. This report is only for in vitro analysis; but employing optical fiber, this can be extended to in vivo analysis too, so that benign tumor could be distinguished without surgery. SUMMARY: In this paper, we have done fluorescence emission spectrum (FES), Stokes' shift Spectrum (SSS) and reflectance spectrum (RLS) of excised benign and malignant tumor tissues (15 each). Of the three modes of spectra, SSS showed the best discrimination. There were four important bands, one at 280nm (due to tryptophan); 320nm (elastin); 355 and 385 (NADH) and 440nm (flavin). From the relative intensities of these bands, three ratios were evaluated. Similarly another four ratios were obtained from reflectance spectra and FES. A statistical analysis of these ratios showed that benign and malignant tissues could be classified with accuracy of 90%.