Study on Damage Characteristics of Fused Silica under Ion Beam Sputtering and AMP Technique

Abstract

Fused silica is an optical material with excellent performance, and it is widely used in the fabrication of optics in various high-power laser systems. With the gradual improvement of laser systems, the quality of optics becomes crucial. Taking magnetorheological finishing (MRF), ion beam sputtering etching (IBSE), and advanced mitigation processing (AMP) as the means, this work focuses on exploring the damage characteristics evolution of fused silica under different techniques. In this work, IBSE technique was used to determinedly polish the optical surface after removing damage layer by MRF technique, and AMP technique was applied to etch the surface with a certain depth. Then, 10 J/cm2 (355 nm, 5 ns) laser was used to irradiate the optical surface, and the damage density of optics maintained at a low level, about 0.001/mm2, which proves that MRF, IBSE, and AMP techniques can effectively improve the laser damage resistance of optics.