Photorefractive Materials, Effects And Devices Prm'93最新文献

{"title":"Implementations of Neural Networks Based on Photorefractive Beam Fanning","authors":"Y. Owechko, B. Soffer","doi":"10.1364/pmed.1993.sac.1","DOIUrl":"https://doi.org/10.1364/pmed.1993.sac.1","url":null,"abstract":"The great success of conventional computers and procedural programming techniques in solving algorithmic problems in science and engineering contrasts with the far slower progress in solving the ill-defined problems at which humans and animals excel, such as recognizing individual faces.","PeriodicalId":110649,"journal":{"name":"Photorefractive Materials, Effects And Devices Prm'93","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128422436","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}

{"title":"Enhancement of Large-Modulation Recording In BSO by the Moving Grating Technique","authors":"W. Gillespie, Z. Wang, C. Cartwright","doi":"10.1364/pmed.1993.thd.14","DOIUrl":"https://doi.org/10.1364/pmed.1993.thd.14","url":null,"abstract":"Bismuth silicon oxide (BSO) has been widely used as a dynamic holographic medium for optical correlation [1], novelty filtering [2,3] and incoherent correlation [4] because of its relatively fast response, reliability and good optical quality over a reasonable surface area.","PeriodicalId":110649,"journal":{"name":"Photorefractive Materials, Effects And Devices Prm'93","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129362974","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}

{"title":"High Two-Wave-Mixing Gain in CdTe:V with an Optimized Low Frequency Alternative Electric Field","authors":"J. Moisan, P. Gravey, N. Wolffer, O. Moine, R. Triboulet, K. Aoudia","doi":"10.1364/pmed.1993.frb.4","DOIUrl":"https://doi.org/10.1364/pmed.1993.frb.4","url":null,"abstract":"The photorefractive effect is now extensively studied in semiconductors, in particular for applications to optical communications.","PeriodicalId":110649,"journal":{"name":"Photorefractive Materials, Effects And Devices Prm'93","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126997295","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}

{"title":"Parametric generation of a spatial subharmonic photorefractive grating in an external dc field with a small electron drift length","authors":"O. P. Nestiorkin, Y. Shershakov","doi":"10.1364/pmed.1993.frd.12","DOIUrl":"https://doi.org/10.1364/pmed.1993.frd.12","url":null,"abstract":"Relaxation of a photorefractive grating with spatial frequency q in external dc field eo is described by well known Kukhtarev equation [1]","PeriodicalId":110649,"journal":{"name":"Photorefractive Materials, Effects And Devices Prm'93","volume":"259 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116233611","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}

{"title":"Combined Effects of Thermal Fixing and Beam Coupling in Photorefractive Materials","authors":"M. Jeganathan, L. Hesselink","doi":"10.1364/pmed.1993.frb.3","DOIUrl":"https://doi.org/10.1364/pmed.1993.frb.3","url":null,"abstract":"To avoid erasure of holograms, recorded in photorefactive materials, during readout several fixing techniques have been used.","PeriodicalId":110649,"journal":{"name":"Photorefractive Materials, Effects And Devices Prm'93","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124985136","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}

{"title":"The Theory of Photorefractive Light Scattering","authors":"V. V. Obuhovsky, A. Stoyanov","doi":"10.1364/pmed.1993.frd.4","DOIUrl":"https://doi.org/10.1364/pmed.1993.frd.4","url":null,"abstract":"Photorefractive crystals are perspective media for the prossesing and storage of holographic information. The most important limitations in their practical application are connected with the arising of strong light scattering (later on it will be named as photorefractive light scattering, PRLS) in the processes of optical recording [1]. In doped crystals LiNbO3, SBN, BaTiO3, etc. the PRLS is manifested so strongly that, in some cases, in can completely suppress the useful effects (image processing ang recording). On the other hand, PRLS is important for \"holographic laser\" operating [2].","PeriodicalId":110649,"journal":{"name":"Photorefractive Materials, Effects And Devices Prm'93","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125671120","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}

{"title":"Picosecond Laser-induced Grating Signals in Cr4+-doped Crystals","authors":"Huimin Liu, W. Jia, A. Leyderman","doi":"10.1364/pmed.1993.thb.14","DOIUrl":"https://doi.org/10.1364/pmed.1993.thb.14","url":null,"abstract":"Cr4+-doped crystals are of current interest in the research of the tunable solid state laser materials.","PeriodicalId":110649,"journal":{"name":"Photorefractive Materials, Effects And Devices Prm'93","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127093444","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}

{"title":"Photostimulated Pyro— and Piezoelctric Local Fields in LiNbO3","authors":"I. F. Kanaev, V. Malinovsky, A. Pugachev, N. Surovtsev","doi":"10.1364/pmed.1993.frc.6","DOIUrl":"https://doi.org/10.1364/pmed.1993.frc.6","url":null,"abstract":"It was reported /1,2/ on a new electric response in LiNbO3 which was not distinguished previously, under a short-time (τp = 50 ns) high-power ruby laser pulse.","PeriodicalId":110649,"journal":{"name":"Photorefractive Materials, Effects And Devices Prm'93","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127734491","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}

{"title":"Dynamics of Magnetophotorefractive Wave Mixing","authors":"P. Johansen, A. S. Jensen","doi":"10.1364/pmed.1993.fre.1","DOIUrl":"https://doi.org/10.1364/pmed.1993.fre.1","url":null,"abstract":"In resonant photorefractive experiments the charge-density distribution in the conduction band is moving and an intrinsic magnetic field proportional to the velocity of the distribution is produced. In such cases the free electron plasma can interact with an externally applied magnetic field. On top of that materials exposed to a magnetic field exhibit Faraday rotation (Voigt birefringence) of the state of polarization of the optical bean.*. The purpose of the present summary is to describe the effect of both phenomena in a standard wave mixing setup. The photorefractive band transport model in the case v here magnetic fields are present is only modified via a term in the current density equation and reads (1) where e is the numeric elementary charge, µ the free electron mobility, n the number density' of free electrons, E the total electric field which may consist of an externally applied term and the norihnear generated spacecharge field, D the diffusion constant, and B the magnetic field term which may consist of an external part and an internal part (stemming from electronic motion). The remaining equations describing the photorefractive effect are the conventional ones. Now, by inferring the small modulation approximation, a perturbational relation for the physical quantities and, by Fourie- transforming in space-time, a steady-state response function for the space-charge electric field are found. ThL photorefractive frequency response function, expressed as a function of the conventional photorefractive parameters, is given by where the function P is given by (3) The actual definition of the parameters in Eqs. (2) and (3) can be found in Ref. [1]. Equation (2) is taken in the case where an externally magnetic field is applied perpendicular to the grating wave vector K. If it is assumed that the constituents of the incident intensity are monochromatic plane waves, that may be frequency shifted a small amount, the Fourier transformation of the perturbed intensity is a sum of δ-functions peaking at k = ±K and at ω = ±Ω. The space-charge field is now given by (4) A typical response function for GaAs:Cr is shown in Fig. 1. The characteristic parameters used in the calculation are taken from Refs. [2, 3, 4], The externally applied electric field is Eθ = 10 V/m, the applied magnetic field is Bθ = 2 T, the angle between the applied electric field and the grating wave vector is 20°, and the angle between the applied magnetic field and the z-axis is 45°. Recently, experiments on photorefr?ctive wave mixing with Faraday rotation in a diluted magnetic semiconductor of Cd] MnTe have been demonstrated. The gain showed an oscillatory behaviour as a function of the' magnetic field, and it was demonstrated that the magnetic field controls the direction and magnitude of the energy transfer. In what follows the coupled wave equations including uie effect of optical activity, the Faraday effect, and the effect of linear absorption will be given. Mcreover, the ","PeriodicalId":110649,"journal":{"name":"Photorefractive Materials, Effects And Devices Prm'93","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129485230","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}

{"title":"Intermode Frequency Nondegenerate Four-Wave Mixing in Planar Waveguides","authors":"E. Shandarov","doi":"10.1364/pmed.1993.frc.15","DOIUrl":"https://doi.org/10.1364/pmed.1993.frc.15","url":null,"abstract":"INTRODUCTION The intermode parametric light scattering experimentally observed in LiNbOQ planar waveguides [11. The weak scattering beams amplified by the pump beam because of the photorefractive grating formation. The frequencies of the scattering and pump beams may be different [21. The present paper is devoted to the analysis of the intermode four-wave frequency-nondegenerate mixing in planar waveguides.","PeriodicalId":110649,"journal":{"name":"Photorefractive Materials, Effects And Devices Prm'93","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121322321","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}