利用紫外激光处理提高熔石英损伤阈值的研究

Research of enhancing damage-thresholds of fused silica using UV laser treatment

为了研究紫外脉冲激光预处理对熔石英表面形貌的影响,验证其对熔石英元件抗紫外激光损伤能力的提升效果,利用输出355nm 3倍频紫外脉冲激光的 YAG 激光器,采用光栅式扫描的方式对熔石英表面进行了全口径能量周期递增的激光预辐照处理,并在处理结束后研究了表面形貌的变化,考核了其在355nm 脉冲激光作用下的损伤阂值。结果发现,石英基片在经过紫外脉冲激光预处理后表面杂质得到有效清除并暴露了低阈值缺陷,处理后的石英基片零几率损伤阈值平均提高24%左右,50%损伤阈值提高约19%。结果表明,紫外激光预处理是增强熔石英元件紫外激光负载能力的有效方法,可有效缓解高功率固体激光装置3倍频输出的负载瓶颈,具备较高的工程运用价值。

In order to study the influence of UV pulse laser pre-treatment on surface image of fused silica and validate its upgrade effect on anti UV laser damage ability of fused silica, using 355nm YAG laser raster to scan fused silica optics by means of power increase by degrees periodically, the change of surface image was studied and its anti-laser damage threshold at 355nm was measured. Test results showed that surface impurity was cleaned out and it was found that the zero probability damage-threshold increased 24% and 50% probability damage-threshold increased 19%. The result proves UV laser pre-treatment is an effective method to increase anti UV laser damage ability and break through the bottleneck of high power laser output at 355nm, laser pre-treatment have practical value in engineering.