Simulation of Laser Ablation of Materials within the Thermal Spike Model

Abstract

Previously, numerical simulations of laser ablation of materials occurring under the action of ultrashort laser pulses in semiconfined samples and samples of finite thickness were carried out. Its thermal mechanism was described in terms of a one-dimensional unsteady heat equation in a coordinate system associated with a moving evaporation front. The action of the laser was taken into account through the source functions in the thermal conductivity equation, specifying the coordinate and time dependences of the laser source. In this work, similar simulations were carried out for semiconfined samples within the framework of a two-temperature thermal spike model, which consisted of two interrelated thermal conductivity equations for the electron gas and the crystal lattice. For the convenience of numerical simulation, in the equations of the thermal spike model, a transition was made to the coordinate system associated with the moving evaporation front of the material. Using numerical simulation, temperature profiles of the electron gas and crystal lattice at different times were obtained, and the dynamics of the temperatures of the electron gas and crystal lattice on the surface of the sample were calculated within the thermal spike model, taking into account the evaporation of the crystal lattice and the emission of electron gas from the surface of the sample. A comparative analysis of the numerical results obtained within both models was carried out.