BR-PVA固体膜在四波混频相干场中的光栅特性和位相共轭波的暂态行为

TEMPORARY RESPONSE OF PHASE CONJUGATION WAVE AND GRATING PROPERTIES IN BR-PVA FILM IN DFWM FIELD

利用Ar离子激光简并四波混频(DFWM)技术,对细菌视紫质(BR)-聚乙烯醇(PVA)固体膜的位相共轭波特性进行了理论和实验研究。采用BR光循环的双态模型和粒子数速率方程,以及全息光栅理论描述了该体系的PC波的衍射效率、时间响应和饱和特性,给出了相应的表达式。讨论了该体系在DFWM场中的光栅机制和上述特性对于输入波的偏振态,强度和强度比,到达样品的时间和形成的初始浓度光栅等参数的依赖关系。实验结果与理论分析相符。

In this paper the theoretical and experimental studies on the properties of phase conjugate (PC) wave and the gratings formed as a result of degenerate four-wave mixing (DFWM) interference field of Ar+ laser in bacteriorhodopsin-polyvinyl alcohol (BR-PVA) solid film are reported. The diffraction efficiency temporary response and saturation property of the PC wave are described by useing a simplified double state model and the method of rate equation combined with a diffraction theory of holograph grating. The mechanism of forming grating in the film and the dependence of the properties mentioned above on polarization states, intensities are analysed. The time of arriving at the sample of three input beams and initial concentration of grating formed in the film are discussed. The theoretical results are in good agreement with the experimental observations.