Fundamental mechanisms of electronic and thermal ejection of material induced by pulsed 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 thermal or electronic mechanism of particle ejection. The two types of processes have been extensively investigated experimentally and a great 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 reports experimental results fitting one or the other mechanism and summarizes the theories describing a thermal or a non-thermal process of laser ablation.