作　　者： ; ; ; ; ; ; ; ;

机构地区： 北京航空航天大学仪器科学与光电工程学院

出　　处： 《光子学报》 2009年第6期1375-1379,共5页

摘　　要： 基于热传导及热弹性力学的基本关系式,建立了激光辐照锗透镜的热力耦合数学物理模型,对瞬态热传导方程和应力平衡方程进行有限元数值求解,得到了锗透镜的温度场和应力场分布,并利用波长1.06μm,脉冲宽度10ns的Nd∶YAG脉冲激光对锗透镜进行了热冲击实验研究.数值分析表明,热应力损伤在锗透镜的脉冲强激光损伤中占据主导地位,在短脉冲激光辐照下,锗透镜出现热应力损伤的激光能量密度小于出现熔融损伤的激光能量密度,热应力损伤主要集中在光斑中心区域并体现为压应力损伤,将使材料表面出现裂纹或剥落,实验结果与数值分析基本相符. The thermal-mechanical physical model of Ge lens irradiated by pulsed-laser was set up based on heat conduction and thermal elastic mechanics theories. The heat conduction differential equation and stress-balance equation were solved by the finite elements method and the transient temperature field and thermal stress field were obtained. Experiment about the thermal shock effect of Ge lens irradiated by Nd ： YAG laser（1. 06μ m, 10 ns）was carried out. The numerical simulation shows that the thermal stress damage dominants in the damage mechanism,thermal stress induced crack lines and flaking off will appear on the lens at low energy density levels,and with more laser energy the melting zone of Ge will be reached. The experiment results match the numerical simulation basically.

关 键 词： 激光损伤 锗透镜 热冲击效应 损伤机理

领　　域： [机械工程] [理学] [理学]