退火参数对熔石英透射波前和损伤阈值的影响

 采用高温退火技术去除熔石英元件表面由于CO2激光修复带来的残余应力,研究了退火环境对元件的表面污染,分析了不同退火温度（600～900 ℃）和保温时间（3～10 h）对于元件残余应力、透射波前、表面粗糙度和激光损伤阈值的影响。结果表明:在800 ℃以下,高温退火10 h可有效去除CO₂激光修复带来的残余应力,对元件的透射波前和表面粗糙度无明显影响;石英保护盒能有效减少退火环境对元件表面产生的污染,但仍有X射线光电子能谱检测不到的表面污染物存在;在退火后采用质量分数为1%的HF刻蚀15 min,激光损伤阈值可恢复,同时元件透射波前和表面粗糙度并无明显的增加。     

Irradiation effects of CO2 laser parameters on surface morphology of fused silica

To understand the surface morphology evolution of fused silica induced by 10.6-μm CO2 laser irradiation at different parameters,this paper reports that optical microscopy,profilometry,and hydrophilicity tests are utilized to characterize the surface structure and roughness of the laser irradiated area. The results show that three typical surface morphologies and two typical hydrophilicity test images are observed at different laser powers and pulse durations. The correlations between surface temperature and surface morphology as well as hydrophilicity behaviours are presented. The different hydrophilicity behaviours are related to surface structures of the laser-induced crater and thermal diffusion area. The thermal diffusion length monotonously increases with increasing laser power and pulse duration. The crater width is almost determined by the laser beam size. The crater depth is more sensitive to the laser power and pulse duration than the crater width.