Predictable surface ablation of dielectrics with few-cycle laser pulse even beyond air ionization

We study surface ablation of dielectrics with single-shot few-cycle optical pulse (∼10 fs) in air, at intensities below and above the onset of air ionization. We perform 3D analysis and careful calibration of the fluence distribution at the laser focus, spanning from linear– to nonlinear– focusing regimes, enabling to thoroughly characterize the severe limitation of the fluence delivered onto the sample surface upon increase of incident pulse energy. Despite significant beam reshaping taking place at high fluence, we demonstrate that it is nevertheless possible to confidently predict the resulting crater profiles on fused silica surface, even in the regime of filamentation.