Ablation of silica glass using pulsed laser plasma soft X-rays

We have investigated ablation of silica glass using pulsed laser plasma soft X-rays. For generating a plasma that emits pulsed soft X-rays, a Ta target was irradiated with focused 532 nm Nd:YAG laser light with a pulse duration of 7 ns at a fluence of 104 J/cm2. The soft X-rays were focused on the surfaces of silica glass using a Au-coated ellipsoidal mirror. The energy density of the soft X-rays can be roughly estimated to be 0.1 J/cm2, which is sufficiently enough for heating silica glass beyond the boiling point. We found that silica glass is smoothly ablated at 40 nm/shot. The processes induced by X-ray irradiation have been discussed based on transient-absorption measurements after X-ray irradiation.