Generation the longitudinal component of electric field on the optical axis using asymmetric binary axicons illuminated by linearly and circularly polarized beams

It is analytically and numerically shown that by introducing the asymmetry into the axicon design it becomes possible to generate the longitudinal electric field (E-field) component on the optical axis for linearly and circularly polarized incident beams. Binary axicons with high numerical aperture (NA) in three configurations (axis-symmetric, spiral and bi-axicon) are investigated. Experimental measurements for the near-field diffraction of linearly and circularly polarized incident beams are presented.