Damage effects of Qswitched Nd:YAG laser beam on IR filter

The film structure determined temperature and standing wave field's characters which formed in laser irradiated optical thin film is presented, the temperature and standing wave fields is calculated for IR filter as an example. The research on damage characters in laser irradiated IR filter is proposed with 1.06μm Qswitched Nd:YAG laser with pulse duration of 10ns and spot diameter of 0.61mm. From the analysis to the laser damaged IR filter, it is discovered that the initial filter damage did occurr in the inner layer, thus the experiment validated the calculated result of temperature and standing wave fields existed in filter. It is valuable to improve the IR filter's hardness against laser.