熔石英相位共轭镜无损工作状态分析

基于非线性光学耦合波方程组建立了聚焦泵浦条件下熔石英玻璃材料中SBS过程的物理模型并编制了相应的数值求解程序,研究了SBS介质内激光场的时空发展特征,从而试图揭示SBS介质的内在破坏机制并寻求相应的加固措施.通过数值模拟程序研究了焦点处激光功率密度以及SBS反射率与激光能量的依赖关系,发现SBS对介质内的激光场具有"限幅"作用,即在注入能量大幅度提升的情况下,内部的激光场强度只有较小的增加,这种机制使大能量的固体介质PCM成为可能.分析激光脉宽以及耦合透镜焦距等参数对SBS过程的影响发现,精细选择系统参数,在熔石英玻璃材料中有可能无损伤地实现高效的SBS过程.

Numerical research on phase-conjugated stimulated Brillouin scattering mirror using fused-silica glass without laser-induced damage

Based on the nonlinear optics coupled wave equations, a physics model of SBS under focal pumping condition was established and numerical codes were developed. The laser field in fused silica glass when SBS existed was thoroughly evaluated and the damage mechanism was exploited. It is found that the optical-limiting-effect makes the laser intensity decrease in the focus spot to a moderate level. The dependence of SBS process on the laser pulse width and focal length of coupling lens was discussed and an operation state with high efficiency and without laser-induce damage was suggested.