High-power laser-induced damage in optical components

In the phenomenon of laser-induced damage there are two regions of pulse duration that exhibit distinctly different damage responses. In short pulse (i.e., psec to a few tens of μsec) lasers the damage response is generally catastrophic in nature and resembles the melting, pitting, and spallation characteristic of the electric breakdown of solid dielectrics. In long pulse lasers, which here include cw and the quasi-cw situation of rep-rate lasers, damage is manifested both catastrophically in fractures and subtly in distortions that result in degraded performance. These apparently different damage responses do not imply that a different set of material and physical properties are operative in the two-time regimes but rather that the interaction time may elevate a particular property in relative importance.