Radially and azimuthally discretized diffractive axicons

Spiral axicons are of interest since they may be used, for example, to generate optical wave fields with propagation-invariant Bessel beam profile and orbital angular momentum, often referred to as optical vortices. Optical vortices are of interest in several fields, for instance, in free-space data communication and micro manipulation. Here, we consider spiral axicons which are discretized in the radial and azimuthal coordinate and compare their performance with continuous spiral axicons. The discretization of the element's structure might be useful in order to obtain additional degrees of freedom for controlling the desired properties of a complex optical wavefield. Various discretization schemes will be considered. In our presentation, we show simulations for the field propagation based on scalar diffraction theory and compare them with experimental measurements.