Enhanced ablation of silica by the superposition of femtosecond and nanosecond laser pulses

We investigate the ablation process in SiO₂ by the superposition of 180 fs laser pulse (_center=800 nm) with a 15 ns laser pulse (_center=532 nm). Compared to femtosecond laser pulses alone, we measured an increase of 270±30% in volume of the ejected material with only a total increase of 40% of lasers fluences. This increase of ablation is the result of thermal and incubation effects generated by the femtosecond laser pulse. PACS 78.20.Nv; 61.80.Ba