熔石英亚表面横向划痕调制作用的3维模拟  

Three dimensional numerical simulation of modulation by transverse crack on fused silica subsurface

作　　者：花金荣[1] 蒋晓东[1] 祖小涛[2] 李莉[2] 陈猛[1] 袁晓东[1] 郑万国[1] 

机构地区：[1]中国工程物理研究院激光聚变研究中心,四川绵阳621900 [2]电子科技大学物理电子学院,成都610054

出　　处：《强激光与粒子束》2010年第7期1441-1444,共4页High Power Laser and Particle Beams

基　　金：国家高技术发展计划项目

摘　　要：建立了熔石英后表面3维横向划痕模型,并采用3维时域有限差分方法对熔石英亚表面划痕周围的电场强度进行了数值模拟,分析了划痕宽度、深度、长度以及划痕倾斜角度对入射光场的调制作用,结果表明：随划痕深度和划痕长度的增加,熔石英内的最大电场强度增大,且当划痕长度达到1μm以上时,最大电场强度趋于稳定;划痕结构因子在1－2之间的划痕较容易引起熔石英损伤;而入射激光在划痕界面和后表面之间发生内全反射时,后表面上的光强增强效果更加明显,因此减少角度范围在20.9°－45°之内的划痕能大幅提高熔石英的损伤阈值。The three-dimensional transverse defect model on exit surface of fused silica was established. Three-dimensional finite-difference time-domain method was used to simulate the electric field intensity distribution in the vicinity of transverse cracks on fused silica subsurface. The modulation of incident light field caused by the width, depth, length and gradient angle of the cracks was analyzed. The results show that the maximal electric field intensity in fused silica will be enhanced as the depth and length increase. The maximal electric field intensity tends to be a constant when the length exceeds 1 μm. The fused silica is more fragile while the crack configuration factor is 1-2. The effect of light intensity enhancement on the rear surface is more obvious when total internal reflection occurs at the transverse crack and the rear surface. Therefore, reducing cracks whose angles are be- tween 20. 9° and 45.0° could increase the damage threshold of fused silica substantially.

关 键 词：时域有限差分 电场分布 激光损伤 横向划痕 

分 类 号：TN012[电子电信—物理电子学]