Stages of laser-radiation damage to the surface of a transparent dielectric

The initial stage of laser-radiation-induced damage to the surface of transparent dielectrics was investigated by electron microscopy and by a study of the disturbed specular reflection under prebreakdown conditions. The deformation of the surface was found to occur before the appearance of a spark. The damage started at isolated points which were evidently structure defects. The various stages of the surface damage of transparent dielectrics were determined.