The comparison of the optical vortices focusing by silicon diffraction axicons and ring gratings with variable relief heights using high-performance computer systems

Abstract

A study was made of the spatial distribution of the intensity of the Laguerre-superGaussian (1,0) modes with circular, radial and azimuthal polarization depending on the change in the height of silicon subwavelength optical elements, the height of which varied from 0.2 to 3 wavelengths. Simulation by the finite difference method in the time domain showed that a change in the height of the considered optical elements significantly affects the diffraction pattern in the near zone. The smallest focal spot size was obtained for "-" circular polarization at an element height equal to two wavelengths.