Propagation of ablation channels with multiple femtosecond laser pulses in dielectrics:: numerical simulations and experiments

We present numerical simulations for the propagation of the ablation channel in dielectrics for multiple incident femtosecond laser pulses with fluences slightly above ultrafast ablation threshold. The theoretical model is based on the direct numerical integration of the wave equation for the laser pulse propagation together with coupled equations for the polarization and ionization of the medium. The progress of the ablation channel predicted by our calculations shows fairly good agreement with that observed in experiments, reproducing quite well other features of the process, namely, formation of optical damage areas aside the channel.