为研究880 nm高功率半导体连续激光器对光学元件的损伤特性, 选择了K9玻璃、ZnSe晶体和无氧铜进行镀膜加工, 形成高反射率和高透过率的光学元件。通过调节到达光学元件表面的平均功率和改变光斑大小来改变光学元件表面的功率密度, 并连续照射30 s, 最终通过显微镜来观察元件的激光损伤形貌。研究结果表明：镀高反膜的K9玻璃在功率密度达到600 W/cm2时, 膜系表面出现烧熔现象, 当达到1 000 W/cm2时出现炸裂现象, 而无氧铜基底镀金反射镜在上述功率密度下未发现损伤；而镀增透膜的ZnSe晶体在激光功率密度高达1 000 W/cm2时, 通过显微镜观察没有发现明显的损伤, 热像仪显示基底温升为5 ℃。

This paper investigates the damage in optical components induced by an 880 nm high-power semiconductor CW laser. The optical components irradiated are high-reflectivity or anti-reflectivity components based on K9 glass, oxygen free copper and ZnSe crystal. The power density of irradiation on component surface is adjusted by changing laser average power and spot size there, and each component is continuously irradiated for 30 s. The laser-induced damage morphology observed by microscope shows that, for K9 glass coated with high-reflectivity film, large-area ablation appears on the surface at the power density of 600 W/cm2 and burst at 1 000 W/cm2. However, no apparent damage is observed on the gilded oxygen free copper and the ZnSe crystal coated with anti-reflectivity film at the above two power densities. Moreover, the temperature rise of ZnSe crystal with anti-reflectivity film is only 5 ℃ measured by thermal imaging system at the power density of 1 000 W/cm2.