Peculiarities of focusing circularly and radially polarized super-Gaussian beams using ring gratings with varying relief height

The focusing features of a super-Gaussian beam, as well Laguerre-super-Gaussian (1,0) modes with radial and circular polarizations on ring gratings (direct inverse) variable height individual relief rings were investigated in this paper. change the from maximum center to minimum at edges element grating) is considered reverse case, when was (reverse grating). comparison carried out action diffractive axicon comparable grating period. Numerical simulation by finite differences time domain method. It shown that direction elements significantly affects diffraction pattern near zone. In particular, for use direct made it possible reduce size focal spot 18.7% polarization ('sigma'=5 μm), led decrease 36.9% ('sigma'=12.25 µm) axicon. also paper illuminated Laguerre-superGauss mode polarization, formation narrow extended region reduced intensity optical axis (optical trap) observed.