Enhancing the Optical Performance of Mid-Infrared Chalcogenide Glass Through Liquid Coating

Laser induced damage to optical component surfaces poses a critical challenge in the development of high-power laser systems. Such damage is typically influenced by its material host, defect distribution, laser parameters, and environmental conditions. The impact of surface defects becomes particularly pronounced under high-power, short-pulse laser irradiation, especially when surface roughness is suboptimal. In this study, we applied a liquid coating method to improve the surface quality of As2S3 glass under various surface conditions by eliminating defects with liquid. A detailed evaluation of the transmittance and surface laser damage threshold was conducted. The results reveal that effective liquid coating significantly reduces surface scattering and Fresnel reflection, resulting in up to a 24.8% increase in overall transmittance and a 2.17-fold improvement in the surface laser damage threshold. These findings underscore the critical role of liquid coating in enhancing optical material performance and offer a practical solution for optimizing high-power laser systems.