The influence of space environmental factors on the laser-induced damage thresholds in optical components

Abstract

Abstract This paper systematically investigated the impact mechanisms of proton irradiation, atomic oxygen irradiation and space debris collision, both individually and in combination, on the laser damage threshold and damage evolution characteristics of HfO2/SiO2 triple-band high-reflection films and fused silica substrates using a simulated near-Earth space radiation experimental system. For the high-reflection film samples, the damage thresholds decreased by 15.38%, 13.12% and 46.80% after proton, atomic oxygen and simulated space debris (penetration) irradiation, respectively. The coupling irradiation of the first two factors resulted in a decrease of 26.93%, while the combined effect of all the three factors led to a reduction of 63.19%. Similarly, the fused silica substrates exhibited the same pattern of laser damage performance degradation. Notably, the study employed high-precision fixed-point in situ measurement techniques to track in detail the microstructural changes, surface roughness and optical-thermal absorption intensity before and after proton and atomic oxygen irradiation at the same location, thus providing a more accurate and comprehensive analysis of the damage mechanisms. In addition, simulations were conducted to quantitatively analyze the transmission trajectories and concentration distribution lines of protons and atomic oxygen incident at specific angles into the target material. The research findings contribute to elucidating the laser damage performance degradation mechanism of transmissive elements in near-Earth space environments and provide technical support for the development of high-damage-threshold optical components resistant to space radiation.