Probing ultrashort-pulse laser excitation of sapphire: From the initial carrier creation to material ablation
Abstract
Ultrashort-pulse laser excitation of dielectrics has been investigated over a large span of intensities. Experimentally, single-shot studies on single-crystal sapphire samples combine time-resolved spectral interferometry with time-resolved reflectivity and ablation-rate measurements. The complete development of the excitation from the first creation of conduction-band electrons at low intensities to the formation of a highly excited plasma and associated material fragmentation is observed experimentally and explained by a single theoretical model, which combines material excitation in a multiple-rate equation description with light propagation. Copyright (C) EPLA, 2014