Diode-pumped all-solid-state ultrafast Cr : LiSGAF laser oscillator-amplifier system applied to laser ablation

We describe a multi-kHz repetition rate ultrafast all-solid-state diode-pum ped oscillator-regenerative amplifier laser system that we have applied to ultrafast laser ablation. The oscillator was a Kerr lens mode-locked Cr:LiS GAF laser and the regenerative amplifier utilised Cr:LiSGAF in a simple thr ee-mirror cavity. The whole laser system, which was pumped by less than 2 W total pump power from four commercially available 670 nm diodes, produced similar to 1 mu J pulses at up to 10 kHz repetition rate, tunable in the ne ar infrared. A simple double pass two grating compressor was used to adjust the pulse duration from 15 ps to 150 fs. Using this laser system we perfor med ablation of stainless steel and fused silica and demonstrated the chara cteristic pulse duration dependence of the ablation threshold for dielectri cs. (C) 2000 Elsevier Science B.V. All rights reserved.