Preparation and laser damage mechanism of stray-light-absorbing thin films in high-energy laser systems

Surface modification is an important way to improve the surface performance of materials, especially for solving the problem of secondary pollution by stray-light-induced damage of aluminum alloy frames in high-energy laser systems. Preparation of aluminum alloy surface-modified functional films and determining the mechanism of system stray light irradiation of the films are of great significance, and they ensure that inertial confinement fusion (ICF) generates clean and sustainable energy. In this study, high-energy-system stray-light-absorbing films were prepared by anodization and electrolysis, followed by microscale and nanoscale characterization and irradiation experiments using single-pulse lasers with different energy densities. The morphologies of the specimens after irradiation were characterized and the damage mechanism of the functional film was investigated. On this basis, a dynamic thermal-mechanical direct coupling model was developed based on the ABAQUS user subroutine/Python for the process of laser irradiation of AA6061, AA6061/Al₂O₃, and AA6061/Al₂O₃/SiO₂. The results indicated that stray-light-absorbing films significantly increase the stray-light absorptivity and effectively reduce the laser irradiation damage of AA6061, thus improving the accuracy and stability of the system.