Numerical simulation of the laser dynamics and laser/matter interactions, and its applications for laser micro-machining

This paper is focused on the systematic computer-based numerical research of processes taking place during laser/matter interaction on the nanosecond time scale. Special attention is paid to the dynamics of a laser with passive Q-switch and intra-cavity nonlinear frequency doubling. The model accounts for the whole set of processes: laser beam attenuation and absorption in the material, heat generation, heat diffusion, phase transitions (solid to liquid, liquid to gaseous state), material removal and melted material re-solidification. Through analysis and simulation of the laser model, we investigate the laser pulse formation and laser parameter optimization. Numerical experiments are used to explain crater shapes, rate of material removal, dependence on laser pulse duration, etc.