Numerical simulations of multi-shot femtosecond laser ablation in dielectrics

In this work, we present numerical simulations for the development of the ablation channel with many incident laser pulses. Our numerical model is based on the direct numerical integration of the wave equation for the laser pulse propagation inside the material since an accurate description of the electric field propagation is required in order to properly include the diffraction of the incoming pulses at the hole entrance, as well as the interference of the multiple reflections on the walls of the channel. The dielectric is simulated as an ensemble of classical harmonic oscillators whose density and frequency are chosen in order to reproduce the main optical properties of the medium