Femtosecond laser ablation by bibursts in the MHz and GHz pulse repetition rates
Andrius Žemaitis, Mantas Gaidys, Paulius Gečys, Martynas Barkauskas, Mindaugas Gedvilas
Abstract
Here, to the best of our knowledge, for the first time we report an in-depth experimental study of high ultrafast laser ablation efficiency for processing of copper and steel with single-pulses, MHz, GHz, and burst-in-the-burst (biburst) regimes. The comparison of burst, biburst, and single-pulse ablation efficiencies was performed for beam-size-optimised regimes, showing the real advantages and disadvantages of milling and drilling processing approaches. Highly efficient ultrashort pulse laser processing was achieved for ∼1 µm optical wavelength: 8.8 µm 3 /µJ for copper drilling, 5.6 µm 3 /µJ for copper milling, and 6.9 µm 3 /µJ for steel milling. We believe that the huge experimental data collected in this study will serve well for the better understanding of laser burst-matter interaction and theoretical modelling.