约束条件下KDP晶体匹配角热敏感性分析方法  

Analysis Method on Phase Matching Angle Thermal Sensitivity of KDP Crystal under Constraint Conditions

作　　者：张森[1,2] 张军伟[2] 李恪宇[2] 李志军[2] 吴文龙[2] 粟敬钦[2] 林东晖[2] 周忆[1] 

机构地区：[1]重庆大学机械工程学院,重庆400030 [2]中国工程物理研究院激光聚变研究中心,四川绵阳621900

出　　处：《中国激光》2016年第7期148-154,共7页Chinese Journal of Lasers

基　　金：国家自然科学基金(61308040)

摘　　要：约束方式和晶体温度是影响磷酸二氢钾(KDP)晶体性能的两个主要因素。晶体在约束条件下,温度的变化使晶体产生热应力和热形变,破坏晶体原有的相位匹配条件,从而致使谐波转换效率降低。为了获得约束条件下温度与晶体匹配角的关系,建立了约束条件下晶体匹配角热敏感性的分析方法。利用有限元分析法,计算约束条件下温度变化产生的热应力和热形变分布;将热光效应、弹光效应以及热形变引入到匹配角的计算之中,获得匹配角的变化规律。以神光Ⅲ原型装置采用的晶体约束方式对该方法进行了验证。结果表明,该方法计算得到的神光Ⅲ原型装置晶体在约束条件下三倍频效率与温度的关系符合效率变化的实际规律。Constraint condition and crystal temperature are two mainly factors that affect the performance of potassium dihydrogen phosphate （KDP） crystals. Under constraint conditions, the original phase matching condition is destroyed and third harmonic conversion efficiency is decreased as a result of thermal stress and thermal deformation caused by temperature variation. An analysis method of crystals thermal sensitivity is established to find the relationship between the temperature and phase matching angle. The finite analysis is used to obtain the distributions of thermal stress and thermal deformation, and then thermal-optic effect, stress-optic effect and thermal deformation are considered to calculate the change law of phase matching angle. The validity and feasibility of method are verified by using crystal constraint condition of SG-III prototype laser facility. The case indicates that the efficiency calculation results of method are better conforming to the actual change law of phase matching angle

关 键 词：材料 磷酸二氢钾晶体 热敏感性 约束方式 温度 三倍频效率 

分 类 号：TB133[机械工程—光学工程]