熔石英亚表面杂质对激光损伤概率的影响

Effect of subsurface impurities of fused silica on laser induced damage probability

基于Mie理论和热传导方程,结合ICP-OES对熔石英亚表面杂质粒子的主要成分测量,建立了计算吸收性杂质粒子诱导熔石英光学元件表面损伤概率的模型。通过该模型理论研究了不同种类的杂质粒子诱导损伤所需的临界能量密度随粒子尺寸的变化,以及不同尺寸分布的杂质粒子诱导熔石英表面的损伤概率。通过损伤实验测试获得了不同光斑尺寸的355 nm激光辐照作用下熔石英表面的损伤概率,与理论计算结果进行对比,在相同粒子分布参数下,分析了三种杂质粒子对损伤概率的贡献(Cu>Al>CeO_2)。通过该模型能够分析光学基底或薄膜亚表面中不同潜在的杂质吸收性粒子对光学元件损伤概率的影响。

Based on Mie theory and heat equation, combined with the measurement of the main components for impurities on the subsurface of fused silica by ICP-OES, a model for calculating laserinduced damage probability on the surface of optical components by absorbing impurities was presented. Based on this theoretical model, the critical fluence required to initiate damage by various impurities as a function of particle radius and the damage probability on the surface of fused silica induced by the impurities with different distribution were investigated. The damage probability on the surface of fused silica was measured under the irradiation of 355 nm laser with different beam sizes. Comparison of the calculated and experimental results was conducted. The contribution to laser-induced damage probability for these three impurities was analyzed （Cu 〉Al〉CeO2） with same particle distribution parameters. Through the model, the effect of various potential absorbing impurities embedded in the subsurface of optical substrates or films on damage probability can be analyzed.