High efficiency femtosecond laser ablation with gigahertz level bursts

The authors report on a simple and easy-to-use GHz amplified femtosecond laser source. The laser source is based on a passively mode-locked oscillator with a near GHz repetition rate. GHz pulses are then selected, and the obtained bursts of pulses are further amplified in a high-power amplifier chain. The presented GHz femtosecond laser source is used with a galvanometric scanner to perform ablation experiments on copper, aluminum, and stainless steel. Specific ablation rates of 0.7, 2.3, and 1.4 (mm3/min)/W are reached. The role of the important experimental parameters, such as the number of subpulses in the burst, is highlighted. Thanks to a specific ablation scheme in the GHz mode, the ablation efficiency is then comparable to the case of single nanosecond pulses, but with the usual quality of femtosecond processing.The authors report on a simple and easy-to-use GHz amplified femtosecond laser source. The laser source is based on a passively mode-locked oscillator with a near GHz repetition rate. GHz pulses are then selected, and the obtained bursts of pulses are further amplified in a high-power amplifier chain. The presented GHz femtosecond laser source is used with a galvanometric scanner to perform ablation experiments on copper, aluminum, and stainless steel. Specific ablation rates of 0.7, 2.3, and 1.4 (mm3/min)/W are reached. The role of the important experimental parameters, such as the number of subpulses in the burst, is highlighted. Thanks to a specific ablation scheme in the GHz mode, the ablation efficiency is then comparable to the case of single nanosecond pulses, but with the usual quality of femtosecond processing.