The mechanisms of particulates sprayed by optical components under intense laser irradiation on the damage performance of dielectric films

In high-power laser facilities, the particulate contaminants originating from damaged optical components play a pivotal role in degrading the laser-induced damage performance of other components. In this study, our attention was centered on high reflectance multilayer HfO2/SiO2dielectric film components. We delved deep into the mechanisms underlying particulate generation and deposition during the damage process and probed into how these particulate contaminants lead to performance degradation of the components. Firstly, we created damage to generate particulates in a sealed environment to investigate the rules of particulates generation and deposition. Then measured the laser induced damage threshold and the morphology of contaminated dielectric film, the laser induced damage threshold decreased by approximately 63.6%-83.5% and the damage morphology varied. We elucidated the modulation mechanisms of particulate contaminants parameters (composition, size, light transmission performance) on the electric field and light intensity by the utilization of multi-physics field simulations, particulate contaminants increased both the peak and range of the electric field/light field around the component during the fundamental frequency laser irradiation. The research results provided a research foundation for inhibiting particulate contaminants generation and removing surface contaminants from optical components in high-power laser facilities.