Comparison of laser induced damage at 1 064 nm and 532 nm to highreflective film fabricated by electron beam evaporation

The damage behaviors of HfO2/SiO2 high reflective optical thin film fabricated by electron beam evaporation (EBE) illuminated using 1 064 nm laser and 532 nm laser showed some difference. It was found that the damage was usually caused by absorptive defects and absorption near the interfaces under the irradiation of 1 064 nm laser, and the damage was caused by electronic defects and absorptive ones under irradiation of 532 nm laser and the former had lower damage threshold. Therefore, the key point to enhance the laser resistance of optical thin films at 1 064 nm was to prevent the presence of the absorptive defects, and to those at 532 nm was to eliminate the electronic defects．