为了研究激光对CCD探测器的损伤效应, 采用有限元分析的方法进行了激光损伤CCD的理论分析和实验验证。阐述了激光辐照CCD探测器的损伤机理, 设计了激光辐照CCD探测器热效应的仿真模型, 针对波长为532nm的高功率激光辐照硅基CCD探测器而产生的热效应, 利用有限元法进行了仿真计算, 得到了CCD探测器受到532nm激光辐照时硅电极的温度曲线以及硅电极损伤时间阈值, 并相应计算出损伤CCD探测器所需要的激光能量阈值为220mJ/cm2左右。结果表明, 损伤阈值随着激光功率密度的增大而减小, 但变化幅度不大;当多脉冲毫秒激光辐照CCD探测器, 在一个脉冲结束、下一个脉冲到来之前, 探测器温度恢复到环境温度。该模型可以较为准确地对单脉冲激光辐照CCD探测器时产生的热损伤效应进行模拟。

In order to explore the damage mechanism of charge-coupled device (CCD) detectors under laser irradiation, CCD detectors irradiated by pulsed laser were analyzed theoretically and verified experimentally based on the finite element method. Damage mechanism of CCD detectors irradiated by laser was described and simulation model of thermal effect of CCD detectors irradiated by laser was designed. Simulation calculation was carried out for thermal effect of silicon CCD detectors irradiated by high power laser at wavelength of 532nm by using finite element method. Temperature curve of silicon electrodes and time threshold of silicon electrode damage were obtained. After calculation, the corresponding laser damage threshold for CCD detector was about 220mJ/cm2. Simulation result shows that damage threshold decreases with the increase of laser power density and but it changes slightly. When multi-millisecond pulse laser irradiates CCD detectors, detector temperature returns to the ambient temperature before the next pulse and after the former pulse. The model can accurately simulate the thermal damage effect of CCD detectors under single laser pulse irradiation.