Annular-aperture diffractive axicons illuminated by Gaussian beams

Abstract

The design for an annular-aperture uniform-axial-intensity diffractive axicon illuminated by a Gaussian beam is given. The stationary phase method and a numerical calculation are applied to investigate the characteristics of the focal segment produced by this kind of diffractive axicon. It is shown that by Gaussian beam illumination of an appropriate beam radius, the axicon can produce a uniform-axial-intensity focal segment with a much more uniform central-core width than that generated by the axicon utilizing plane wave illumination.