对多层介质膜光栅以及介质膜反射镜的激光损伤阈值进行了系统的研究。测试方法采用国际测试标准。测试结果表明,介质光栅的损伤阈值远低于未刻蚀的多层介质膜。对样品损伤形貌的扫描电镜照片分析发现,相比于未刻蚀的多层介质膜,介质膜光栅的初始损伤主要发生在光栅槽形的侧壁,且损伤主要是由驻波场的空间分布引起的本征吸收、制备过程中引入的杂质污染以及刻蚀过程中HfO2的化学计量机失衡引起的。
Laser-induced damage thresholds of multi-layer dielectric mirrors and multi-layer dielectric gratings were investigated in this paper. Experimental results indicate that the damage threshold of multi-layer dielectric mirrors was larger than that of multi layer dielectric gratings. Damage morphologies were observed by using scanning electron microscope. It was found that the initial damage occurred at the edge of the groove for multi-layer dielectric gratings. The following factors resulted in decreasing of laser-induced damage threshold for multi layer dielectric gratings: the electric filed distribution induced intrinsic absorption, the pollution induced absorption during manufacture process and the unbalance in stoichiometry of HfO2 film.