化学刻蚀过程中熔石英表面沉积物的形成及其对激光损伤的影响

化学刻蚀是提升熔石英光学元件抗激光损伤性能的重要后处理技术之一,但刻蚀后熔石英表面附着的沉积物对其表面质量、透射性能和抗激光损伤性能有很大影响。使用光学显微镜和原子力显微镜表征了化学刻蚀后附着于熔石英表面的沉积物的微观形貌,并分析了其形成机理；X射线能谱分析表明化学刻蚀后熔石英表面沉积物主要由Fe，Ni，Al等元素的金属盐组成。损伤阈值测试结果表明熔石英表面高密度沉积物区域的损伤阈值明显低于非沉积物区域,沉积物对熔石英光学元件的抗激光损伤性能产生严重影响,它们是诱导熔石英激光损伤的前驱体。

Formation of redeposit in chemical etching process of fused silica and its effect on laser-induced damage

Chemical etching is one of the major post-processing techniques to improve laser-induced damage performance of fused silica optics, but deposits adhered to the surface of etched optics affect the surface quality, transmission performance and laser-induced damage resistance of fused silica a lot. In this work, optical microscope and atomic force microscope (AFM) were used to characterize the surface morphology of deposits adhered to the etched surface of fused silica. In addition, the formation process of the deposits was analyzed. Energy dispersive X-ray analysis shows that deposits adhered to the surface of etched fused silica are mainly composed of metallic salts of Fe, Ni and Al elements. Damage threshold test results show that the areas with high density deposits on fused silica surfaces have lower damage thresholds than the areas with few deposits. So redeposits adhered to the etched surface have the great influence on laser damage performance of fused silica, they are precursors inducing laser-damage of fused silica.