Focus shaping of linearly polarized pseudo-nondiffracting beam using a radial shift and a large numerical aperture

Abstract Based on vector Debye integral, focusing properties of linearly polarized Bessel-Gaussian beam modulated by Bessel gratings (BGMBG) combining a radial phase shift modulated spiral zone plate (RSSZP) passing through a large numerical aperture (NA) lens system are investigated. The data obtained lead that the intensity and the phase distributions in the focal section are significantly controlled by the order of the beams (m, n), the topological charge p and the shifting parameter of the RSSZP. Simulations show that by increasing the topological charge, the radius of the ring increases and that the shifting parameter has an effect on the ring size. Also, the linear polarized incident beam lost its polarization after crossing a high-numerical-aperture objective.