TIME DEPENDENCE OF THE OPTICAL-BREAKDOWN THRESHOLDS OF GLASSES UNDER THE ACTION OF SINGLE-FREQUENCY LASER-RADIATION

The dependence of the optical breakdown thresholds of K8 glass on the pulsewidth of laser radiation with a wavelength of 1.054 mu m has been measured in the range from 4 X 10(-10) to 3 X 10(-8) sec, with the ra diation focused at a spot with various diameters from 0.5 to 20 mu m. It is shown that, when self-focusing is absent, the intrinsic optical breakdown threshold of the glasses is independent of the radiation pul sewidths. (C) 1996 The Optical Society of America.