Influence of ejected SiO2 particles on the laser damage thresholds of fused silica

Abstract

The SiO2 particles ejected during the laser-induced damage of fused silica will be re-deposited on its surface as secondary contaminants, which seriously reduce the laser damage thresholds of the components. In this article, the influence of the secondary contaminants on the laser damage resistance of the fused silica optical components was investigated by using two test protocols for ion beam etching (IBE), dynamic chemical etching (DCE), and reactive ion etching (RIE)+DCE treated samples, which are the most optimized methods for the surface treatment of fused silica. Results showed that there are obvious differences in the damage thresholds of samples treated by different processes, with the smallest effect on the damage threshold of the RIE+DCE treated sample and the most significant effect on the damage threshold of IBE treated sample. These results may facilitate further optimization of the above surface treatment methods, which will be potentially used for the treatment of fused silica elements applied in high-power laser facilities.