重频应用下等离子体电光开关热退偏损耗分析  

Depolarization loss analysis of electro-optic crystal KDP heated by repetition frequency laser

作　　者：张君[1] 张雄军[1] 魏晓峰[1] 吴登生[1] 田晓琳[1] 曹丁象[1] 董军[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

出　　处：《强激光与粒子束》2008年第2期229-233,共5页High Power Laser and Particle Beams

基　　金：国家高技术发展计划项目

摘　　要：基于有限元数值方法,给出电光晶体KDP在高平均功率激光负载下温度场分布和应力场分布。在此基础上得到了折射率随温度变化、电光系数随温度变化、及应力双折射引入的退偏损耗。数值模拟显示:电光系数随温度变化和应力双折射是引起开关退偏损耗的主要因素。当入射激光平均功率为40 W、辐照时间为420 s时,KDP晶体最高温度为38.43℃,电光系数随温度变化及应力双折射引入的最大退偏损耗分别为2.38%和4.04%。实验测量了应力双折射导致的退偏损耗,实验结果和理论结果符合较好。Temperature and thermal stress distributions in the KDP, heated by repetition frequency laser, are given by means of finite element methods. Depolarized loss, which is induced by temperature dependence of the refractive index, electrooptic coefficient, and by thermal-stress, is calculated. The simulated results indicate： variation of electro-optic coefficient as well as stress birefringence is the main factor, which induces depolarized loss of the switch. When the average power of the incident laser is 40 W, after 420 s irradiation, the highest temperature in KDP crystal is 38.43℃. The largest depolarized loss induced by variation of electro-optic coefficient and stress birefringence is correspondingly 2. 38%, 4. 04%. Depolarized loss, induced by stress birefringence, is measured. The measurements on KDP crystal support the analytical results.

关 键 词：电光开关 退偏损耗 热应力 应力双折射 有限元法 KDP 

分 类 号：TN248.1[电子电信—物理电子学]