Diagnosis of optical film laser damage based on characteristics of plasma

Whether to diagnose accurately the laser damage of optical film or not is the key to measure the laser-induced damage threshold of the optical film, which directly affect the accurate assessment. In this paper, based on the plasma theory, researches on the characteristics of the laser-induced plasma while the optical film has been damaged in detail have been done, and theoretical and experimental analyzing on this plasma shockwave has been taken with acoustic method. The laser damage diagnosis method of optical film based on the characteristics of plasma has been proposed. The results show that, this method, taken the atomic spectrum of the laser-induced plasma spectrum and the peak value of pressure of the laser-induced plasma shockwave as the criteria, can efficiently improve the test accuracy of the laser-induced damage threshold of optical film.