Diffractive optical elements for the generating cylindrical beams of different orders

The paper proposes a method for calculating the phase function of subwavelength diffractive optical elements. The method is based on diffraction gratings with a varying period for generating vector beams with arbitrary-order cylindrical polarization. Formulas for the phase function of the grating are obtained with due regard for the period variation for increasing the efficiency of the polarization conversion of the incident beam. The obtained phase functions are supposed to be used for creating polarization-conversion diffractive optical elements for noise-resistant optical communication systems.