The application of laser-induced damage spot size effect for laser conditioning mechanism

Abstract

We propose the spot-size effect in laser-induced damage to optical thin films as a method to investigate the defect removal model which is one of the laser conditioning mechanisms, and the theoretical and experimental studies are presented. A standard deviation σ 2 is set up for fitting the damage thresholds which are obtained by multi-spot size test. The laser conditioning effect on ZrO 2 /SiO 2 multilayer high reflective films is analyzed through this application. It is found that the mean distance of two initiating defects is increased by laser conditioning, which means that the defect density is decreased. Thus, the initiating defects are removed partially by laser conditioning. Furthermore, the intrinsic damage threshold of the film is little affected through the laser conditioning process.