共查询到20条相似文献，搜索用时 78 毫秒
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本文简要叙述了光折变效应的基本物理概念和它的特点，具体地介绍了光折变晶体ＢａＴｉＯ３的自泵浦位相共轭效应、两波耦合效应、光感生的光散射效应等主要物理特性，并给出了有关工作的最新实验结果．简析了光折变晶体的研究现状和今后发展趋势． 相似文献
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光折变晶体的热透镜效应 总被引：4，自引：0，他引：4
通过对光折变晶体的热透镜效应的理论分析发现,光通过光折变晶体时,只有在晶体发生双折射的前提下,才能发生热透镜效应。并指出,晶体内存在的由热效应引起的横向各向异性温度梯度仅是产生热透镜效应的一个方面,而“光阻”则是产生光折变晶体热透镜效应的另一个原因,从而丰富了光折变效应的内涵。 相似文献
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掺杂钾钠铌酸锶钡光折变晶体的各向异性衍射 总被引：3，自引：0，他引：3
本文给出了关于光折变晶体各向异性衍射的二波耦合方程,还给出了三种分别掺Cu,Ce,Co的钨青铜结构系列单晶(厚度为0.6—0.8cm)钾钠铌酸锶钡(KNSBN)在He-Ne激光(λ=6328?)照射下产生的光致光栅衍射实验结果。根据二波耦合理论,解释了这三种光析变晶体的衍射图样分布。根据波矢图的分析得出结论:对于不同性(正或负)单轴晶体,只能存在一种各向异性衍射的圆环图样(e→o衍射或o→e衍射)。理论分析与实验基本符合。关键词： 相似文献
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INCOHERENTLY COUPLED SCREENING-PHOTOVOLTAIC SOLITON FAMILIES IN BIASED PHOTOVOLTAIC PHOTOREFRACTIVE CRYSTALS 总被引：1，自引：0，他引：1 
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下载免费PDF全文 It is shown that the existence of incoherently coupled screening-photovoltaic soliton families is possible in biased photovoltaic photorefractive crystals under steady-state conditions. These screening-photovoltaic soliton families can be established provided the multiple incident beams have the same polarization and wavelength, and are mutually incoherent. Such soliton families reduce to screening-photovoltaic soliton pairs when they contain only two components. Relevant examples are presented where the photovoltaic photorefractive crystal is of the lithium niobate type. 相似文献
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Zheng Wu Yihe Zhang Cong Fang Ke Ma He Lin Yanmin Jia Jianrong Chen Yu Wang Helen Lai Wa Chan 《physica status solidi (a)》2014,211(3):641-644
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AbstractThe theory of the nonequilibrium charge carrier transport in unipolar multivalley semiconductors is developed. It is shown that the diffusion of photoexcited nonequilibrium heavy and light electrons in multivalley semiconductors is a correlated process, like the ambipolar diffusion in the case of the electron-hole plasma. The light-induced intervalley transitions, resulting in the imbalance between the subsystems of the light and heavy electrons, give rise to the electromotive force (emf) through the mechanism of the Dember photovoltaic effect. The value of the emf occurring in the ‘metal-semiconductor-metal’ structure is calculated in the linear approximation in terms of the light intensity as a small parameter. It is shown that the emf is determined by the conductivity of heavy and light electron subsystems, as well as by the surface conductivity of the metal-semiconductor interface. 相似文献
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We have investigated the transport and ultraviolet photovoltaic propertiesof Fe$_{3}$O$_{4}$ thin films grown on glass substrates by facing-targetsputtering technique. The nonlinear dependence of current-density on voltagesuggests that the transport process is most likely the tunnelling process andgrain boundaries act as barriers. Furthermore, nonequilibrium electron-holepairs are excited in the grains and grain boundary regions forFe$_{3}$O$_{4}$ film under ultraviolet laser, since the energy gap ofFe$_{3}$O$_{4}$ is smaller than the ultraviolet photon energy. And then thebuilt-in electric field near the grain boundaries will separate carriers,leading to the appearance of an instant photovoltage. 相似文献