Effect of sample temperature on femtosecond laser ablation of copper

Abstract

We conduct an experimental study supported by theoretical analysis of single laser ablating copper to investigate the interactions between laser and material at different sample temperatures, and predict the changes of ablation morphology and lattice temperature. For investigating the effect of sample temperature on femtosecond laser processing, we conduct experiments on and simulate the thermal behavior of femtosecond laser irradiating copper by using a two-temperature model. The simulation results show that both electron peak temperature and the relaxation time needed to reach equilibrium increase as initial sample temperature rises. When the sample temperature rises from 300 K to 600 K, the maximum lattice temperature of the copper surface increases by about 6500 K under femtosecond laser irradiation, and the ablation depth increases by 20%. The simulated ablation depths follow the same general trend as the experimental values. This work provides some theoretical basis and technical support for developing femtosecond laser processing in the field of metal materials.