Thermal ablation behavior of infrared optical element under high energy CW laser

Thermal ablation is quite a complex process in high energy continuous wave (CW) laser facility, and it is crucial to understand the damage mechanism for stable operation of laser system. In this paper, we observe the behavior of contaminants-induced damage via a self-build optics testing platform. The waveband of optical coatings (Ta2O5 and SiO2) under test is dedicated for the infrared. Based on 100kW level infrared CW laser, the thermal ablation process of the optical coatings and the substrate caused by typical surface contaminants (iron micro-particle) is recorded, which shows distinct results in many aspects. This work can be helpful for understanding the influence of contaminants and prevent the optical elements from thermal damage in high energy laser system.