Extraordinary spin to orbital angular momentum conversion on guided zone plates

Abstract Focusing systems with high numerical aperture can be used to convert spin angular momentum into orbital efficiencies of 50%, while for low apertures this conversion vanishes. In paper, based on the properties binary Fresnel zone plates, we propose a structure that is achieved by making an accurate selection width and depth rings. This allows us obtain large increase in resulting focusing fields, it also has special characteristic obtained higher structures, where standard do not work. The ability system perform extraordinary demonstrated FDTD methods analytical model developed using combination guided mode theory Stratton–Chu diffraction theory.