DETECTION OF LASER DAMAGE TO THE SURFACES OF MATERIALS AND COATINGS WITH THE AID OF AN INDUCED GAS-DISCHARGE

A method for detection of laser damage to the surfaces of optical mate rials and coatings was investigated. The damage was detected with the aid of a gas discharge induced by the products of a laser ablation plu me, A suitable selection of the parameters of the detection system mad e it possible to investigate laser surface damage at radiation intensi ties W > 130 MW cm(-2) (lambda = 1.06 mu m, t(p) = 10 ns). A special f eature of the electric response was that the result was determined sol ely by the occurrence of damage and not by its nature or by the laser damage threshold. This feature makes the method suitable for automatic damage detection systems used in statistical investigations.