Multithreshold Measurement and Analysis of Pulsed Laser Damage on Optical Surfaces.

摘要

The methodology of multithreshold analysis, a new approach to laser-damage research, is described. The comparison of thresholds for various damage-related effects identifies dominant failure mechanisms and provides better guidance for laser-materials technology. After a brief description of apparatus, the procedure for routinely measuring up to eight different thresholds per sample is given. The maximum-likelihood principle is used to derive an algorithm for computing thresholds and standard deviations. The use of a standard gold sample to verify reproducibility and to maintain long-term calibration is discussed. Examples of multithreshold results on uncoated and coated infrared optical components are presented. The following are some of the effects for which thresholds are compared: slip, roughening, cracking, pits, melting, craters, delamination of coatings, ion and light emission, and work function change. (Author)