检索结果-内蒙古大学图书馆

PHOTONIC INTERMODULE CONNECTOR USING 8X8 OPTICAL SWITCHES FOR NEAR-FUTURE ELECTRONIC SWITCHING SYSTEMS

IEICE TRANSACTIONS ON COMMUNICATIONS 1994年第2期E77B卷 155-162页

作者： HIMENO, A NAGASE, R ITO, T KATO, K OKUNO, M NIPPON TELEGRAPH & TEL PUBL CORP OPTOELECTR LABS TOKAI IBARAKI 31911 JAPAN

A photonic inter-module connector for near-future electronic switching systems is demonstrated through the use of silica-based 8 X 8 optical switches. A small-scale switch matrix is sufficient because the near-future systems will consist of a limited number of modules. If an active module is affected by a fatal fault or accident, a stand-by module must quickly take its place. The experimental photonic inter-module connector can switch 156-Mbit/s photonic interconnections between seven subscriber-line-concentrator modules and eight circuit-switching modules.

关键词： PHOTONIC SWITCHING OPTICAL SWITCH OPTICAL INTERCONNECTION wave-guides AND OPTICAL COMMUNICATION

来源：评论

学校读者我要写书评

暂无评论

STUDY OF OPTICALLY wave-GUIDING STRUCTURES FORMED IN POTASSIUM TITANYL PHOSPHATE BY ION-EXCHANGE

引用

OPTICAL ENGINEERING 1994年第8期33卷 2632-2637页

作者： LIPOVSKII, AA NIKONOROV, NV LOKALOV, VA SI VAVILOV STATE OPT INST ST PETERSBURG 193171RUSSIA

Ion-exchanged KTiOPO4 (KTP) planar optical waveguides are formed in X, Y, and Z cuts of KTP single crystals with Rb+ --> K+, Cs+ --> K+, and Ag+ --> K+ ion exchanges from nitrate melts. waveguide modes, index profiles, and birefringence of the waveguides are studied with the integrated optics technique. Electron probe microanalysis is applied to determine an elemental composition of the ion-exchanged structures and x-ray diffractometry is used to study crystalline structure of the waveguides. The research enabled us to produce KTP optical waveguides by silver ion diffusion for the first time. In addition, the residual potassium concentrations after the ion exchange are measured and the distribution profiles of Cs and Rb atoms and positions of the atoms in the KTP lattice are characterized. A study of the unit cell deformations accompanied by birefringence measurements enabled us to clarify differences in Rb+ --> K+ and Cs+ --> K+ ion exchanges. A novel approach that would produce a KTP optical waveguide with higher index increase and better crystalline perfection than Rb+ --> K+ and Cs+ --> K+ ion exchanges is proposed.

关键词： INTEGRATED OPTICS wave-guides CRYSTALS DIFFUSION CHARACTERIZATION

来源：评论

学校读者我要写书评

暂无评论

Spatial distribution of refractive index variations induced in bulk fused silica by single ultrashort and short laser pulses

引用

JOURNAL OF APPLIED PHYSICS 2007年第4期101卷 43506-1-43506-页

作者： Burakov, I. M. Bulgakova, N. M. Stoian, R. Mermillod-Blondin, A. Audouard, E. Rosenfeld, A. Husakou, A. Hertel, I. V. Russian Acad Sci Inst Thermophys SB Novosibirsk 630090 Russia Univ St Etienne CNRS UMR 5516 Lab Hubert Curien F-42000 St Etienne France Max Born Inst Nichtlineare Opt & Kurzzeitspektros D-12489 Berlin Germany Free Univ Berlin Dept Phys D-1000 Berlin Germany

We correlate phase-contrast microscopy of modification tracks induced by tightly focused single ultrashort and short laser pulses inside fused silica with numerical simulations of nonlinear laser excitation footprints. Different pulse durations on the femtosecond and picosecond range are compared in order to validate the experimental and theoretical observations on the subsequent refractive index variations in a regime where linear and nonlinear contributions play a comparable role. The nature of the laser-induced structural changes depends essentially on the characteristics of pulse propagation in different regions of the irradiated zone. Numerical simulations of laser pulse propagation in the excited region show that accumulation of excess energy and swift nonlinear absorption contribute to the formation of either positive or negative phase-shift regions within the same single-pulse-induced damage trace. The decrease in the refractive index can be unambiguously correlated with the regions of maximum energy deposition during prolonged exposure times.

关键词： FEMTOSECOND-LASER wave-guides MICROSCOPY ABSORPTION GLASSES MEDIA PHASE

来源：评论

学校读者我要写书评

暂无评论

Cascaded third-harmonic generation of ultrashort optical pulses in two-dimensional quasi-phase-matching gratings

引用

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS 2007年第9期24卷 2394-2405页

作者： Fujioka, Nobuhide Ashihara, Satoshi Ono, Hidenobu Shimura, Tsutomu Kuroda, Kazuo Tokyo Univ Agr & Technol Dept Appl Phys Koganei Tokyo 1848588 Japan Univ Tokyo Inst Ind Sci Meguro Ku Tokyo 1538505 Japan Japan Sci & Technol Corp PRESTO Kawaguchi Shi Saitama 3320012 Japan

Cascaded third-harmonic generation (THG) of femtosecond pulses in a two-dimensional periodically poled lithium niobate is demonstrated experimentally. The poling pattern satisfies quasi-phase-matching conditions for both second-harmonic generation (SHG) and the following sum-frequency generation. The pulse-front tilt in noncollinear interactions compensates for group-velocity mismatch among fundamental, second-harmonic (SH), and third-harmonic (TH) pulses, thereby achieving broad acceptance bandwidths in SHG and THG. A 2 mm thick device generates SH and TH pulses of 106 and 110 fs, respectively, from fundamental pulses with temporal duration of 118 fs and a 1568 nm center wavelength. The frequency conversion properties are studied theoretically, and the optimal focusing condition for maximum conversion efficiency is derived. (c) 2007 Optical Society of America.

关键词： POLED LITHIUM-NIOBATE NONLINEAR PHOTONIC CRYSTALS LIMITED FUNDAMENTALPULSES SAPPHIRE LASER-PULSES 2ND-HARMONIC GENERATION FEMTOSECOND PULSES QUADRATICNONLINEARITIES HARMONIC-GENERATION SINGLE-SOURCE wave-guides

来源：评论

学校读者我要写书评

暂无评论

Gain and carrier temperature response of semiconductor laser media to short optical pulses

引用

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS 2000年第5期17卷 840-850页

作者： Sarkisyan, TV Rosenberger, AT Oraevsky, AN Bandy, DK Oklahoma State Univ Dept Phys Stillwater OK 74078 USA Oklahoma State Univ Ctr Laser & Photon Res Stillwater OK 74078 USA Russian Acad Sci PN Lebedev Phys Inst Moscow 117924 Russia

The gain and carrier temperature response of semiconductor laser media to picosecond optical pulses with various pulse energies is obtained by means of a model that is based on rate equations extended to include the carrier energy density equation. The temperature dynamics are obtained from the carrier energy density by use of a quasi-equilibrium Fermi-Dirac distribution. We study the cases of media whose prepulse states are strongly absorbing, transparent, and strongly amplifying at the frequency of the pulse. The results show that the various physical processes that influence the gain and carrier temperature contribute differently, depending on both the initial state of the medium and the pulse energy. In particular, the influence of free-carrier absorption and two-photon absorption on the dynamics of the carrier temperature and the gain coefficient is discussed in detail. (C) 2000 Optical Society of America [S0740-3224(00)01305-9]. OCIS codes: 320.0320, 320.5390, 320.7130, 250.5980, 190.5970, 190.4720, 140.5960.

关键词： Guide saturable absorbers Nonlinear gain wave-guides Dynamics Amplifiers Propagation Saturation Diodes Gaas Formulation Saturated gallium arsenides temperature response diodes Amplifiers gain coefficient waveguide Device Component Gain Optical pulses Semiconductor lasers dynamics pulse energy Vital Signs

来源：评论

学校读者我要写书评

暂无评论

Superlinear photovoltaic currents in LiNbO₃:: analyses under the two-center model

引用

APPLIED PHYSICS B-LASERS AND OPTICS 2004年第3期79卷 351-358页

作者： Carnicero, J Caballero, O Carrascosa, M Cabrera, JM Univ Autonoma Madrid Fac Ciencias Dept Fis Mat C4 E-28049 Madrid Spain

Superlinear photovoltaic currents in LiNbO3 are theoretically studied by using a two active center model, with Fe2+/Fe3+ as primary center and Nb-Li(4+)/Nb-Li(5+) as secondary center. Analytical instead of numerical results are provided, including close-form expressions for most common experimental situations. Recent photovoltaic parameters obtained for alpha-phase proton-exchanged LiNbO3 waveguides (very similar to the substrate) are used for applying the model and comparing with published experimental results. Thoroughly studied aspects are: the redistribution of donor/acceptor states for each species as a function of the light intensity, their contribution to the photovoltaic current density, the effect of the temperature, and the role of the center concentrations and their reduction state. This provides a detailed understanding of the photovoltaic current function shapes versus light intensity, predicts new features of interest for experimentalists and suggests further experiments to better determine the material parameters. Photovoltaic measurements and modeling appear a simpler and safer way of understanding the role of the two-center photovoltaic effect in photorefractive phenomena as well as for determining important photorefractive parameters.

关键词： HIGH LIGHT INTENSITIES BENZOIC-ACID VAPOR wave-guides LITHIUM-NIOBATE PHOTOREFRACTIVE MATERIALS CRYSTALS ERASURE High intensity light PHOTOVOLTAIC PHOTOVOLTAIC EFFECT Supralinearity Lithium niobate crystals waveguide Device Component Light intensity

来源：评论

学校读者我要写书评

暂无评论

MOMENT METHOD ANALYSIS OF A HORIZONTALLY POLARIZED OMNIDIRECTIONAL SLOT ARRAY ANTENNA

引用

IEE PROCEEDINGS-MICROwaveS ANTENNAS AND PROPAGATION 1995年第1期142卷 1-6页

作者： SANGSTER, AJ WANG, H Dept. of Comput. & Electr. Eng. Heriot-Watt Univ. Edinburgh UK

An entire domain moment method analysis of an omnidirectional linear array antenna, in which the radiating elements are slot doublets in a rectangular waveguide, has been developed. A particular feature of the analysis is that direct computation of internal mutual coupling between broadwall slots on opposing walls has been incorporated. Numerical solutions are presented for the scattering properties of the slot doublets in both air-filled and dielectric-filled waveguides. The results are shown to be in good agreement with network analyser measurements.

关键词： MOMENT METHODS wave-guides SLOT ANTENNAS

来源：评论

学校读者我要写书评

暂无评论

Fabrication of microchannels in glass using focused femtosecond laser radiation and selective chemical etching

引用

APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING 2006年第1-2期84卷 47-61页

作者： Hnatovsky, C. Taylor, R. S. Simova, E. Rajeev, P. P. Rayner, D. M. Bhardwaj, V. R. Corkum, P. B. Natl Res Council Canada Inst Microstruct Sci Ottawa ON K1A 0R6 Canada Natl Res Council Canada Steacie Inst Mol Sci Ottawa ON K1A 0R6 Canada Univ Ottawa Dept Phys Ottawa ON K1N 6N5 Canada

We use the combination of femtosecond laser dielectric modification and selective chemical etching to fabricate high-quality microchannels in glass. The photoinduced modification morphology has been studied in fused silica and in borosilicate glass BK7, using ultra-high spatial resolution techniques of selective chemical etching followed by atomic force or scanning electron microscopy. The analysis shows that the high differential etch rate inside the modified regions, is determined by the presence of polarization-dependent self-ordered periodic nanocracks or nanoporous structures. We also investigate the optimum irradiation conditions needed to produce high-aspect ratio microchannels with small symmetric cross-sections and smooth walls.

关键词： TRANSPARENT MATERIALS SILICA GLASS FUSED-SILICA wave-guides REPETITION-RATE PULSE-LASER SURFACE INDEX MICROFABRICATION INTERFACE

来源：评论

学校读者我要写书评

暂无评论

Non-reciprocal ultrafast laser writing

引用

NATURE PHOTONICS 2008年第2期2卷 99-104页

作者： Yang, Weijia Kazansky, Peter G. Svirko, Yuri P. Univ Southampton Optoelect Res Ctr Southampton SO17 1BJ Hants England Univ Joensuu Dept Math & Phys FI-80101 Joensuu Finland

Photosensitivity is a material property that is relevant to many phenomena and applications, from photosynthesis and photography to optical data storage and ultrafast laser writing. It was commonly thought that, in a homogeneous medium, photosensitivity and the corresponding light-induced material modifications do not change on reversing the direction of light propagation. Here we demonstrate that when the direction of the femtosecond laser beam is reversed from the +z to -z direction, the structures written in LiNbO3 crystal when translating the beam along the +y and -y directions are mirrored. In a non-centrosymmetric medium, modification of the material can therefore differ for light propagating in opposite directions. This is the first evidence of a new optical phenomenon of non-reciprocal photosensitivity. We interpret this effect in terms of light pressure and associated heat flow, resulting in a temperature gradient in homogeneous media without inversion symmetry under uniform intense irradiation.

关键词： FEMTOSECOND LASER LITHIUM-NIOBATE TRANSPARENT MATERIALS wave-guides REPETITION-RATE SILICA GLASS FUSED-SILICA PULSES WRITTEN FABRICATION

来源：评论

学校读者我要写书评

暂无评论

New organic inorganic sol-gel material with high transparency at 1.55 μm

引用

OPTICS COMMUNICATIONS 2005年第4-6期253卷 346-351页

作者： Oubaha, M Kribich, RK Copperwhite, R Etienne, P O'Dwyer, K MacCraith, BD Moreau, Y Dublin City Univ Sch Phys Sci Opt Sensors Lab Natl Ctr Sensor Res Dublin 9 Ireland Univ Montpellier 2 Lab Verres UMR 5587 F-34090 Montpellier France Univ Montpellier 2 Ctr Electr & Microoptoelect Montpellier UMR 5507 F-34090 Montpellier France

New sol-gel derived organic/inorganic hybrid single mode waveguides devices have been developed for telecommunication applications in the two near infrared windows at 1310 and 1550 nm. The overall fabrication procedure of these devices is described and the refractive indices of the guiding, buffer and protective layers are adjusted by the precise control of the material composition. Due to the improved composition of the guiding layer, the attenuation losses are significantly decreased to 0.5 and 1.5 dB/cm, respectively, at 1310 and 1550 nm. (c) 2005 Elsevier B.V. All rights reserved.

关键词： HYBRID MATERIALS wave-guides

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：