Nonlinear propagation calculation-based irradiation process control for several mJ ultrashort pulse laser processing

Abstract

In the realm of ultrashort pulse laser processing, surpassing the air ionization threshold, variations in focusing characteristics due to nonlinear optical phenomena pose challenges. Particularly, suitable irradiation conditions and position control methods for high pulse energy processing around 1 mJ remain unestablished. This study explores laser divergence phenomena in the high pulse energy range, examining both experimental and computational data. Quantitative demonstrations of laser focusing alterations, including divergence position and fluence, were achieved. Additionally, the dry laser peening effect was enhanced by energy-specific irradiation control. Numerical simulation-based visualization facilitates precise control, advancing the processing techniques.