ROLE OF INTERFACE ABSORPTION IN LASER-INDUCED LOCAL HEATING OF OPTICAL COATINGS

Considering the interface absorption in optical coatings, we propose a model to simulate interface absorption. Calculations are made and the temperature field of several kinds of thin film multilayers, includin g those of partial reflectivity, high-reflectivity, and antireflectivi ty coatings are analyzed. The interface absorption is found to greatly influence the temperature distribution within multilayer coatings and to weaken the laser damage resistance of the samples. The real-time r esults of the photothermal deflection technique for laser induced dama ge to samples supports the model. (C) 1997 Society of Photo-Optical In strumentation Engineers.