Laser induced damage of high reflective coatings prepared by different deposition methods in vacuum and air

The vacuum laser damage experimental facility was established. The samples of Hf22/SiO2 high reflective coatings were prepared by electron beam evaporation and ion assisted technology. The laser induced damage thresholds(LIDT) of samples were determined.The damage behaviors of the samples in vacuum and air environment were different. The results showe that the 1∶1 and R∶1 LIDTs of coatings in vacuum decreased about 30% compared with those inair, which might be caused by different thermal diffusion processes.