用1064nm激光增强HfO2/SiO2薄膜的抗激光损伤能力的实验研究

 用1 064nm激光实验研究了HfO₂/SiO₂薄膜的激光损伤增强效应，实验以薄膜激光损伤阈值70%的激光能量开始，采用N-ON-1方式处理薄膜，激光脉冲的能量增量为5J/cm²。实验结果表明，激光处理薄膜表面能使激光损伤阈值平均提高到3倍左右，并且薄膜的损伤尺度也明显减小。对有缺陷的薄膜，其缺陷经低能量激光后熔和消除，其抗激光损伤能力得到增强，但增强得并不显著，而薄膜本身的激光预处理，可以使其激光损伤阈值大大提高。

Damage threshold improvement of HfO2/SiO2 coating by 1 064nm laser conditioning

In this paper, the Nd:YAG laser with wavelength 1 064nm is used to study the improvement effect of damage threshold of HfO2/SiO2 coating samples. The experiment of laser conditioning effect was taken by use of JV-on-1 mode, namely the irradiation energy density started from about 70% of the damage threshold, and increased 5 J/cm2 energy pulse by pulse until serious damage appeared. The experiment results show that 1064 nm laser irradiation can improve the damage threshold of HfO2/SiO2 coating up to 3 times. The mechanisms of laser conditioning on HfO2/SiO2 mirror are found in two forms: laser annealing and laser cleaning of coating. Laser annealing can increase the damage threshold of non-defective coating up to 3 times on the average. Laser cleaning means that coating defects such as nodular are cleaned by low energy density irradiation, and the coating damage threshold improved to a certain extent. The anti-damage ability of the coating can improve 3 times, and the effect is permanent.