Radially and Azimuthally Polarized Beams Generated by a Composite Spiral Zone Plate

Abstract

We present a diffractive method for obtaining azimuthal and radially polarized beams. This method involves a modified half-wave plate, a composite spiral zone plate, a pinhole and a lens. Two composite spiral zone plates are combined and assisted by a pinhole and a lens, to transform a circularly polarized beam into a radially polarized or an azimuthal polarized beam. This method is investigated numerically using diffraction theory. The field distributions on the focal spot of the composite spiral zone plates and the output cylindrical beams are calculated. Finally, the use of this method to generate cylindrical vector beams is validated.