ABLATION OF METALS BY ULTRASHORT LASER-PULSES

Ablation of metal targets by Ti:sapphire laser radiation is studied. T he ablation depth per pulse is measured for laser pulse durations betw een 150 fs and 30 ps and fluences ranging from the ablation threshold similar to 0.1 J/cm(2) up to 10 J/cm(2). Two different ablation regime s are observed for the first time. In both cases the ablation depth pe r pulse depends logarithmically on the laser fluence. A simple theoret ical model for a qualitative description of the experimental results i s presented. (C) 1997 Optical Society of America.