Simulation of the Optical Vortices Generation by the Silver Spiral Zone Plates

Abstract

The formation of an optical vortex by a silver spiral zone plate was presented by using the finite-difference time-domain method implemented in FullWVE (RSoft). Both the left and right circularly polarized Gaussian beams at the wavelength of 532 nm have been used as an incident light. Spiral zone plate with the topological charge of 2 μm the diameter of 8 μm and the focal length of 532 nm made in 100 nm silver film produces an optical vortex with the maximum intensity of 55 a.u. at the focal plane.