Dynamics of electronic excitations involved in laser-induced damage in HfO and SiO films.

The dynamics of electron excitations associated with the initiation of laser-induced damage in hafnia and silica monolayer films are investigated using time-resolved damage testing involving a pair of 0.7 ps pulses with adjustable delay and laser pulse fluences. Results in hafnia indicate that the relaxation profile depends on the pump-pulse fluence (initial excitation), and as a result, it exhibits an effective lifetime that is variable. Analogous experiments in silica form two different types of damage morphologies that are observed on different ranges of delay times.