Experimental Investigation on Laser Pretreatment of Optical Films

Abstract

Optical films have been prepared on K9 glass by electronic beam evaporation. Parameters of S-polarized Nd: YAG laser used for pretreatment and damage tests are: wavelength is 355nm, pulse width is 8ns, and incidence angle is 33.75 degree. The results reflect that: the influence of laser pretreatment on laser induced damage threshold of films is uncertain. Laser pretreatment not always improve the laser induced damage threshold of films, and sometimes it will cause negative influence. As for damage probability, for a certain testing energy density, there is an energy density scope, pretreatment pulse with energy density in which can reduce the laser induced damage probability of films. The energy density of laser pretreatment pulse should be selected according to the serving conditions of films.