DIFFRACTION OF THE GAUSSIAN BEAM ON LAYERED LENS AND SIMILAR A CONICAL AND DIFFRACTION AXICONS

In this paper we consider the possibility of replacing the diffraction axicon and the conical axicon on the gradient lens with a linear variation of the refractive index. Analytically and numerically using the finite-difference time- domain method we performed a comparative study of the Gaussian beam dif- fraction on diffraction mikro-axicon, conical axicon and gradient microlens consisting of subwavelength layers. The parameters under consideration the types of elements estimated in the depth of focus and a transverse dimension of beam.