共查询到18条相似文献,搜索用时 93 毫秒
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提出了有偏压光伏光折变晶体中存在着明暗矢量孤子,它起源于对外电场的非均匀空间屏蔽和光伏效应.当光伏效应为零时,这些明暗矢量孤子就转化为明暗矢量屏蔽孤子,其物理系统就转化为明暗矢量屏蔽孤子的物理系统;当外电场为零时,这些明暗矢量孤子预言了明暗矢量光伏孤子,其物理系统预言了明暗矢量光伏孤子的物理系统.应用光束传播的方法讨论了这些明暗矢量孤子的稳定性.结果表明,当σ> 0 和(β+α-δ) > 0 时,在(β+α-δ)小于某一值的区域内,这些明暗矢量孤子是稳定的;其中σ为控制两光束强度的参数,β为与外偏压有关的参数,α和β为与晶体的光伏系数有关的参数;当σ<0和(β+α-δ) <0时,在(β+α-δ)大于某一值的区域内,这些明暗矢量孤子也是稳定的. 相似文献
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为了得到温度和强度对高斯光束在串联光折变晶体回路中自偏转的影响结果,假设一束暗孤子光束和一束高斯光束分别入射到串联光折变晶体回路中的两块晶体上,利用数值计算方法分析了暗孤子的最大光强或所处晶体温度变化对与明孤子匹配的高斯光束自偏转特性的影响.结果表明,高斯光束的偏转程度随暗孤子最大光强增加而增大,随晶体温度的升高而减小.这些结果对光控光器件、温控光器件的工程实现具有重要的参考价值。 相似文献
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温度对光伏光折变晶体中高斯光束演化的影响 总被引:3,自引:2,他引:1
为了得到温度对有偏压光伏光折变晶体中高斯光束演化特性的影响结果,基于暗辐射强度对温度的依赖关系,研究了不同温度下高斯光束在光伏光折变晶体中的动态演化。将高斯光束作为入射波,采用数值方法求解波传播方程,当温度是300K时,与晶体匹配的高斯光束可演化成稳定的屏蔽光伏明孤子;当温度变化较大时,高斯光束变得不稳或者发散。在失配的条件下,通过改变晶体的温度能使一不稳定的高斯光束变成一稳定的明孤子波。结果表明,这种温度增加或减少控制下的光伏光折变晶体中高斯光束演化特性的改变有望应用于温控光器件。 相似文献
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为了研究有外加电场的双光子光折变介质中匹配高斯光束的动态演化及自偏转特性,采用数值模拟的方法,给出了匹配高斯光束在晶体中的动态演化及自偏转图形。结果表明,对于给定的与双光子光折变介质参量匹配的高斯光束,在介质中能演化为稳定的孤子波;考虑扩散效应之后,匹配高斯光束的光束中心将发生自偏转;随着外加电场的增加,高斯光束的自偏转程度增加,当外加电场达到一定强度后,高斯光束的自偏转程度随着外加电场的增加反而减小;高斯光束的自偏转程度随着入射光强的变化关系与外加电场的情况相似。 相似文献
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证明了有偏压的光伏光折变晶体中存在着明、暗稳态的空间孤子-屏蔽光伏孤子.它起源于对外电场的非均匀空间屏蔽和光伏效应。同已报道的稳态光折变空间孤子相比,它具有不同的特性。当外电场为某一值时,用改变外电场的极性和旋转光的偏振方向可以实现从明屏蔽光伏孤子转换为暗屏蔽光伏孤子或从暗屏蔽光伏孤子转换为明屏蔽光伏孤子。 相似文献
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We theoretically investigate the evolution of dark screening spatial solitons originating from the quadratic electro-optic effect in biased centrosymmetric photorefractive (CP) crystal by using beam propagation method (BPM). The results indicate that the multiple dark solitons sequence can be obtained in the CP crystal with the odd or even initial conditions. If the initial width of the dark notch is smaller, only a fundamental soliton or a Y-junction soliton pair is generated. When the initial width of the dark notch and the bias electric field are increased, the multiple dark spatial solitons sequence is formed, which realized a progressive transition from a low-order soliton to a higher-order solitons sequence in both odd and even conditions. The solitons characteristic is similar to that of screening solitons in the non-centrosymmetric photorefractive (NCP) crystals. 相似文献
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V. B. Voloshinov K. B. Yushkov 《Journal of Communications Technology and Electronics》2007,52(6):678-683
Double acoustooptic diffraction of light in a paratellurite crystal is investigated experimentally and theoretically. The anisotropic Bragg interaction with three diffraction maxima is considered in the case when two monochromatic light beams are incident on the crystal simultaneously. For each beam, double diffraction is realized, so that the propagation direction of one of the beams coincides with the propagation direction of the second-order diffracted ray for the other beam. It is shown that the diffraction pattern consists of three diffraction maxima: two of these are formed by the zero- and second-order diffracted rays, while the third maxima is formed by the first-order diffracted rays. The possibility of summation of the radiation intensities at the diffraction maxima is analyzed. 相似文献
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A. M. Glass D. von der Linde D. H. Auston T. J. Negran 《Journal of Electronic Materials》1975,4(5):915-943
Optical absorption in pyroelectric crystals is accompanied by electrical effects (in addition to the well-known pyroelectric
effect) which are not present in other materials. Optical excitation between localized states gives rise to an instantaneous
macroscopic polarization change due to the change of dipole moment at the absorbing center. Excitation of free carriers from
localized states will in general result in a bulk photovoltaic effect due to asymmetric charge transfer. Thus spatially non-uniform
illumination gives rise to internal fields, resulting in refractive index variations. Studies of these effects for fast detection,
optical logic, memories, and microwave generation will be described. 相似文献