Craters and nanostructures on BaF2 sample induced by a focused 46.9nm laser

Abstract

We successfully damaged BaF2 samples by a 46.9nm capillary discharge laser of 100μJ focused by a toroidal mirror at a grazing incidence. Ablation craters with clear boundaries were detected by optical microscope and atomic force microscope (AFM). Laser-induced nanostructures with a period of ∼1μm were observed in the ablation area under single pulse irradiation and multiple pulses irradiation. The surface behavior was compared and analyzed with that induced by the laser of 50μJ. The nanostructures were supposed to be attributed to the thermoelastic effect and the period of the structures was effected by the energy of the laser.