Fresnel diffraction of Humbert beam of type-II by a helical axicon

The current study examines the diffraction of Humbert beam of type-II by a helical axicon based on the diffraction integral formula. The considered beam is a new donut beam family which generated by converting the Bessel-Gaussian beams passing through a paraxial ABCD optical system with a SPP. For the diffracted beam produced by the stationary phase approach, we have formulated the intensity distribution. By adjusting the input beam features and the topological charge of the helical axicon, numerical simulations are carried out to examine the behavior of the diffracted beam.