Hydrodynamic Simulation of the Femtosecond Laser Processing of Metals

Abstract

The electron-ion collision frequency is a key factor for simulations of the interaction process of ultrashort lasers with metals. In this paper, we propose a semiempirical method based on the Drude-Sommerfeld model for obtaining the electron-ion collision frequency over a wide temperature range, from solid-state to high-temperature plasma. Moreover, we performed a series of hydrodynamic simulations including the modified electron-ion collision frequency. The results indicated that the modified electron-ion collision frequency can exactly describe not only the energy deposits of various femtosecond laser pulses but also the transient properties of electrons on the metal surface. Moreover, a simple function was identified to describe the relationship between laser intensity and peak electron temperature on the surface. This mothed is expected to be beneficial for simulations of the interaction process of femtosecond laser pulses with metals.