Modeling for Copper Ablation by Ultrashort Laser Bursts-Train

Abstract

Ablation of copper using multipulse femtosecond laser irradiation with an 800 nm wavelength and 900-fs pulse duration is investigated theoretically using a dynamic tow temperature model. Our results show that the irradiation of a metal film by burst femtosecond laser with a separation time between pulses less than the thermal relaxation time can dramatically enhance the irradiated focal volume without a significant dissipation of the energy inside the material. We demonstrate the advantage of burst irradiation at low fluence where the cooper can be ablated below single ablation threshold. We also suggest that at high fluence, irradiation with a burst-train may give rise to a cleaner ablation than with a pulse-train.