Femtosecond laser surface structuring of silicon with Gaussian and optical vortex beams

Abstract We report an experimental analysis of femtosecond laser induced surface structuring of silicon by exploiting both Gaussian and Optical Vortex beams. In particular, we show how different surface patterns, consisting of quasi-periodic ripples and grooves, can be obtained by using different states of polarization offered by optical vortex beams. Both for Gaussian and optical vortex beams, an increase of the number of laser pulses, N, or beam energy, E 0, leads to a progressive predominance of the grooves coverage, with ripples