Ablation of (111) and (001) Crystal Plates by Ultrashort Laser Pulses with Rotated Linear Polarization

The dependence of the threshold fluence for surface ablation of such crystalline materials as silicon and diamond (with orientations (001) and (111)) on the direction of linear polarization of ultrashort pulses of different duration (0.3–3.3 ps) with a wavelength of 515 nm has been studied for the first time. The obtained values of the ablation fluence threshold demonstrate for all oriented plates a noticeable dependence on the az-imuth of the laser pulses polarization for all three durations. The azimuthal modulation of the value ranges from 30 to 90% and is associated with the width of the band gap for different crystallographic directions of these crystalline materials, appearing upon laser polarization coinciding with these directions. The results obtained will allow to optimize the polarization parameters of ultrashort laser pulses for processing various crystalline materials.