Photorefractive Materials, Effects, and Devices最新文献_第7页

Analytic and Numeric Results on Subharmonics in BSO BSO 中次谐波的分析和数值结果

Photorefractive Materials, Effects, and Devices Pub Date : 1992-05-22 DOI: 10.1364/pmed.1991.wc22

A. Błȩdowski, B. Sturman, J. Otten, K. Ringhofer

引用次数: 0

Forward Phase-Conjugate Wave in Degenerate Four-Wave Mixing (DFWM) in Photorefractive Crystalline Slab 光折变晶体板中简并四波混频(DFWM)中的正向相位共轭波

Photorefractive Materials, Effects, and Devices Pub Date : 1992-05-22 DOI: 10.1364/pmed.1991.tuc24

H. Zhang, X. H. He, S. Tang

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Spatial Subharmonic Generation at Intermode Interaction in Planar Waveguides 平面波导中模间相互作用的空间次谐波产生

Photorefractive Materials, Effects, and Devices Pub Date : 1992-05-22 DOI: 10.1364/pmed.1991.wc25

V. Popov, E. Shandarov, S. Shandarov

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Non-steady-state photoEMF in crystals with long relaxation times of photoconductivity 具有长光导弛豫时间的晶体中的非稳态光电动势

Photorefractive Materials, Effects, and Devices Pub Date : 1992-05-22 DOI: 10.1364/pmed.1991.tuc6

I. Sokolov, S. Stepanov

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On the Buildup and Decay of Photorefractive Wave Mixing Processes 光折变波混频过程的累积与衰减

Photorefractive Materials, Effects, and Devices Pub Date : 1992-05-22 DOI: 10.1364/pmed.1991.mb2

M. Horowitz, B. Fischer

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Elasto-optic and roto-optic contribution to the photorefractive effect 弹性光学和旋转光学对光折变效应的贡献

Photorefractive Materials, Effects, and Devices Pub Date : 1992-05-22 DOI: 10.1364/pmed.1991.tuc13

M. Zgonik, P. Günter

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Electron-Hole Competition in InP:Fe -- The Role of Multiple Defects InP:Fe中电子-空穴竞争——多重缺陷的作用

Photorefractive Materials, Effects, and Devices Pub Date : 1992-05-22 DOI: 10.1364/pmed.1991.mc3

R. S. Rana, D. Nolte

{"title":"Electron-Hole Competition in InP:Fe -- The Role of Multiple Defects","authors":"R. S. Rana, D. Nolte","doi":"10.1364/pmed.1991.mc3","DOIUrl":"https://doi.org/10.1364/pmed.1991.mc3","url":null,"abstract":"The photorefractive effect has now been identified and studied in many semi-insulating III-V compound semiconductors [1]. In general, it can be well described by a Single Defect Model (SDM) with one or two types of charge carriers. However, discrepancies arise between theory and the experimental results due to the presence of additional defects. In understanding the role of multiple deep defects in the photorefractive effect, temperature plays a key role. Each different defect has a specific energy position within the bandgap of the material. Thermal emission of carriers trapped at defect sites is a strong (exponential) function of defect energy and the sample temperature. The thermal relaxation of nonequilibrium defect occupancies, and the subsequent effect on the photorefractive effect, can be studied by monitoring the two-wave mixing (2WM) gain and four-wave mixing (4WM) diffraction efficiency as functions of temperature, providing a natural tool to characterize the material. We find that multiple defect levels in InP:Fe lead to dramatic changes in the photorefractive behavior. Reduced gain reported at room temperature can be shown to arise from an additional defect in InP other than isolated Fe.","PeriodicalId":355924,"journal":{"name":"Photorefractive Materials, Effects, and Devices","volume":"113 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116081142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Detection of the transient motion of a scattering surface by two-wave mixing in a photorefractive crystal 用光折变晶体中的双波混合检测散射表面的瞬态运动

Photorefractive Materials, Effects, and Devices Pub Date : 1992-05-22 DOI: 10.1364/pmed.1991.wc8

R. Ing, J. Monchalin

{"title":"Detection of the transient motion of a scattering surface by two-wave mixing in a photorefractive crystal","authors":"R. Ing, J. Monchalin","doi":"10.1364/pmed.1991.wc8","DOIUrl":"https://doi.org/10.1364/pmed.1991.wc8","url":null,"abstract":"Optical detection of the transient surface motion of objects is an area of far reaching practical importance. Applications include the vibration monitoring of many engineering structures (power plants, aircrafts, engines of various kinds...) and more recently the detection of ultrasound produced by pulse laser excitation. This technique, now in active development in our laboratory and elsewhere, extends ultrasonic inspection of materials to conditions otherwise difficult or impossible (complex geometries, hot products on a production line...). Various optical systems have been devised for detecting surface motion and have been recently reviewed1. We are reporting here the novel use of two wave mixing in a photorefractive crystal for detecting such a motion and in particular ultrasonic displacement produced by pulsed laser excitation. This approach has the merit of being applicable to a rough surface by integrating over many speckles and of having a very broad frequency detection bandwidth. The use of two-wave mixing for coherent homodyne detection of arbitrary wavefronts was previously reported and applied to the detection and amplification of an intensity modulated wave2. In the case of interest here of the detection of surface motion, the signal wave which has been scattered off the surface is instead phase modulated, and the scheme previously reported cannot be directly used since the transmitted signal wave and the diffracted pump wave, which acts as local oscillator, are in phase. Linear and sensitive detection of phase shifts requires instead the interfering light fields to be in quadrature. Before describing an optical configuration which satisfies this requirement, we analyze the effect of a small phase shift applied to the signal wave in a two-wave mixing configuration.","PeriodicalId":355924,"journal":{"name":"Photorefractive Materials, Effects, and Devices","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129052712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Detection of Low Intensity Optical Wavefronts Using Noise Reduction Techniques in Photorefractive Amplifiers 利用光折变放大器中的降噪技术检测低强度光波前

Photorefractive Materials, Effects, and Devices Pub Date : 1992-05-22 DOI: 10.1364/pmed.1991.mc6

H. Rajbenbach, A. Delboulbé, J. Huignard

引用次数: 0

Anisotropic Diffraction in Photorefractive Volume Hologram 光折变体全息图的各向异性衍射

Photorefractive Materials, Effects, and Devices Pub Date : 1992-05-22 DOI: 10.1364/pmed.1991.wa7

Ching-Cherng Sun, M. Chang

引用次数: 0