Modeling of the temperature field in nanosecond pulsed laser ablation of single crystalline diamond

Abstract

In this paper, a comprehensive finite element (FE) simulation model of the heat transfer for laser ablation of a single crystalline diamond (SCD) with a scanning laser beam in Gaussian shape is developed. The model takes into account the material properties, the geometric structure, and the thermal boundary conditions. It is employed to study the dependence of the temperature distribution under varying laser machining parameters. The distribution characteristics of the temperature field, the temperature evolution, and the heat conduction on the diamond surface are obtained, analyzed, and discussed. The law describing the influence of the laser parameters on the temperature field on the diamond surface is established. After comparing the numerically estimated thermal penetration depth of the pulsed laser in the diamond with the experimentally ablated groove characterized by a scanning electron microscope (SEM), a white light interferometer (WLI) and the Raman spectroscopy analysis of the deposited metamorphic layer, it is found that the developed model shows an excellent predictive capability and provides a promising tool for the future optimization of the machining parameters.