FUNDAMENTAL MECHANISMS OF ELECTRONIC AND THERMAL EJECTION OF MATERIALINDUCED BY POISED LASER-BEAMS

Laser ablation is a process which starts with absorption of the laser radiation followed by electronic excitation which may give rise to a t hermal or electronic mechanism of particle ejection. The two types of processes have been extensively investigated experimentally and a grea t deal of phenomenological information have been gathered. Theoretical treatment provides, in the first case, a model based on thermodynamic properties of the solid surface and in the latter case refers to the electronic characteristics of the solid. The present brief overview re ports experimental results fitting one or the other mechanism and summ arizes the theories describing a thermal or a non-thermal process of l aser ablation.