Phenomenological modeling for femtosecond laser processing of fused silica

In this work, a phenomenological laser ablation model is developed to predict the ablation morphology of fused silica irradiated by femtosecond single and multiple pulses. It couples the changes in the surface morphology of fused silica and the impact of the incubation effect on the subsequent laser pulse processing. The key parameter of the model, which is defined as the material removal thickness induced by unit laser fluence, is determined by comparing with experimental data. This enables the simulation of cross sectional profile ablated by laser pulses at varying fluences, as well as the prediction of crater depth and radius. The average relative errors of predicting the depth and radius are calculated as 2.48% and 1.91%, which confirms the effectiveness and accuracy of the model. Furthermore, the present model is used to simulate micro grooves and three-dimensional microstructures ablated by multiple pulses, which provides guidance for experimental design and parameter selection of femtosecond laser processing.