激光预处理中薄膜损伤形貌对预处理效果的影响

采用亚阈值激光能量对光学元件进行激光预处理后，其损伤阈值可以提高两三倍。在激光预处理过程中，不可避免地会使光学元件产生损伤，若产生的损伤不影响光学元件的使用性能，则原则上可以接受。首先介绍了HfO2/SiO2多层高反膜S-on-1损伤阈值测试方法，实验研究了激光预处理过程中光学薄膜元件的损伤过程，分析了预处理过程中薄膜损伤形貌对其光学性能及抗激光损伤阈值的影响。结果表明，对膜系为G/（HL）11H2L/A的HfO2/SiO2多层高反膜进行激光预处理，最外层SiO2层的破坏不影响薄膜整个反射率曲线。相反，由于消除了HfO2层的节瘤缺陷，薄膜的损伤阈值得到大幅度的提高。

Effects of damaged appearance of coatings on its conditioning during laser conditioning

The damage threshold can increase 2-3 times through laser conditioning optical component using the subthreshold laser energy. In the process, it will make the optical component produce damage inevitably, if the damage does not affect the optical performance, which is acceptable in principle. In this paper, the S-on-1 LIDT of hafnia silica multilayer high reflective coatings was introduced firstly. Experimentally, the damage process of optical coatings during laser conditioning was studied. At the same time, the laser damage appearance that affected the optical capability and LIDT of coatings was analyzed. The result is, with the film system of G/(HL)11H2L/A, after laser conditioning for the HfO2/SiO2 multilayer HR coatings, the destroyed of outermost SiO2 coating can not affect its spectrum performance. Reversely, the LIDT of coatings is enhanced sharply because removing the nodula in the next HfO2 coating.