GENERATION THE LONGITUDINAL COMPONENT OF ELECTRIC FIELD ON THE OPTICAL AXIS USING ASYMMETRIC BINARY AXICONS ILLUMINATED BY LINEARLY AND CIRCULARLY POLARIZED BEAMS Khonina S. N. 3.2. <...> E-mail: khonina@smr.ru Abstract: 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 (axissymmetric, spiral and bi-axicon) are investigated. <...> Experimental measurements for the near-field diffraction of linearly and circularly polarized incident beams are presented. <...> Index terms: asymmetric binary axicon, near-field diffraction, longitudinal electrical field component INTRODUCTION The axicon is known to generate a zero-order Bessel beam with the central spot size for intensity FWHM = 0.36λ/NA [13], which is 37% smaller than the Airy disk produced with a similar NA lens. <...> Thus, the axicons hold promise for applications where a compact transverse light spot is required. <...> However, if the incident beam is linearly polarized (as in most lasers), a decrease in the focal spot size generated by the total electromagnetic field intensity is hindered by the contribution of the longitudinal component, which increases with increasing NA, thus increasing the focal spot transverse dimension along the polarization axis. <...> With a radially polarized incident beam, the high NA axicon produces a focal spot mainly composed of a single longitudinal component, thus enabling one to break the diffraction limit associated with a lens in compliance with the scalar theory prediction [1 – 6]. <...> It has been demonstrated [9, 10] that using a linearly polarized beam incident on a high NA binary axicon it is possible to generate a longitudinal component on the optical axis with use of a phase jump perpendicular to the polarization axis. <...> However, this effect is only observed at a definite mutual position of the polarization axis and the bi-axicon. <...> Note that Ref. [10] also reported on the research of a spiral binary axicon capable of operating independently of the linearly polarized beam axis. <...> A linearly polarized laser beam can rather easily be transformed into a circularly polarized beam, which retains a circular symmetry even <...>