非相干背景光辐照二波耦合中的最佳匹配随机共振  

Optimal matching stochastic resonance in two-wave mixing with incoherent background beam

作　　者：谢美华[1] 

机构地区：[1]国防科技大学理学院,湖南长沙410073

出　　处：《国防科技大学学报》2014年第3期36-40,共5页Journal of National University of Defense Technology

基　　金：国家自然科学基金资助项目(61205190)

摘　　要：针对非相干背景光辐照二波耦合中参数的最佳匹配设计问题,提出了一种基于随机共振理论的研究方法。首先,文章通过二波耦合过程进行物理机理分析和数值实验分析,证明了该问题在本质上可归结为一种随机共振现象。其次,从随机共振的角度,研究其中的最佳参数设计问题,给出了一种分布处理的最优参数设计流程。按照该方法,在给定增益要求的情况下,先根据信号光饱和与否来确定晶体长度,最后根据非相干光的比例对增益的影响来确定非相干光的比例。仿真实验表明,经过最佳参数设计后,信号的增益和输出信噪比上均有显著提高。In photorefractive two-wave mixing system with incoherent background beam,many parameters in system will affect the efficiency of mixing.To solve the optimal designing of parameters,a new method based on stochastic resonance（SR） was put forward.Firstly,by analyzing the two-wave mixing process through physical and numerical way,the stochastic resonance essence was discovered in the two-wave mixing.Secondly,a new method for optimal matching parameters designing was suggested from the aspect of SR.In this new method,for the given gain requirement,the length of crystal was decided according to the saturation of signal firstly,and then the ratio of incoherent light was decided by its affection to gain.Numerical results showed that both the SNR and the gain are improved after the optimal designing of parameters.

关 键 词：二波耦合 非相干光 随机共振 最佳匹配 

分 类 号：O437[机械工程—光学工程]