#479 Anton Nalimov Optimizing of Poynting vector and light intensity after a secant gradient lens

#479 Anton Nalimov "Optimizing of Poynting vector and light intensity after a secant gradient lens"
In this work, the focusing of a beam with circular polarization and a second-order phase vortex and a second-order cylindrical vector beam by a Mikaelian gradient lens were simulated. It is shown numerically that in the focus of these beams a region is formed where a projection of the Poynting vector on the Z axis is negative, therefore, there is a region with a reverse energy flow. By adding a cylindrical cutout to the output surface of the lens, optimizing it, and optimizing the height of the lens, one can get a focal spot where, unlike other previous works, the region with the reverse energy flow will not be at the local minimum of intensity, but at the maximum of intensity on the optical axis. That is, this lens cam be used as an “optical magnet”, attracting Rayleigh particles (with a diameter of 1/20 wavelength or less) to its surface.