Improvement of the laser-induced damage resistance of optical coatings in vacuum environments

Abstract

Two measures were presented to improve the laser-induced damage resistance of the optical films used in vacuum environments. Firstly, the impact of a few O2, N2 and He2 introduced in vacuum on the laser-induced damage threshold of the dielectric mirror coatings were investigated. Then, laser conditioning effects in atmosphere environments on the laser-induced damage threshold of the dielectric mirror coatings used in vacuum environments were also investigated. It was found that a few O2, N2 introduced in vacuum can effectively improve the laser damage resistance of the optical films in vacuum environment due to the resistance to air-vacuum effect. However, a few He2 have no this effect on laser induced damage threshold (LIDT) of the films. In addition, laser conditioning in atmosphere can also effectively improve the LIDT of the optical thin films used in vacuum environment.