Mechanical damage in transparent solids caused by laser pulses of different durations

Abstract

A mechanical damage of transparent solids caused by local laser-produced heating is considered. Applicability of thermoelasticity equations to the analysis of the mechanical stage of laser damage is substantiated for both short and ultrashort pulses. Damage criteria have been obtained for the crack-formation mechanism. On the basis of these criteria, the conditions for the transition from the crack-formation damage to defect generation and ablation have been clarified. The analysis can be applied to both intrinsic (impact and multiphoton ionization) and extrinsic (initiated by absorbing inclusions) absorption mechanisms of laser radiation.