Degradation of optical components induced by production on aluminum alloy surface irradiated by stray light

The degradation of optical components presents a critical impediment to the advancement of energy within intense laser systems, with splatter contamination induced by sustained irradiation of stray light onto aluminum alloy structural components serving as the primary factor for the diminished resistance of optical components to laser-induced damage. This study investigated the physicochemical properties of splatter contaminants resulting from repeated exposure of aluminum alloys to stray light and their effects on the performance of optical components. Following grazing angle irradiation by nanosecond fundamental frequency lasers, an elliptical surface ablation pattern was observed on the aluminum alloy, accompanied by a significant decline in the optical performance of reflective mirrors. Finite element calculations were employed to analyze the influence of laser irradiation frequency and fluence on the microstructural changes of aluminum alloys. The gasification depth and width variations were largely governed by laser fluence and pulse count, with simulation results demonstrating experimental results. This research effectively identifies the origins of surface contaminants on optical components within intense laser systems, laying a foundation for designing system components and strategies for clean control.