title: Depth-minimized, large period half-wave corrugation for linear to radial and azimuthal polarization transformation by grating-mode phase management.
abstract: The transformation of the polarization distribution of a laser beam from linear to radial and azimuthal by means of a subwavelength binary corrugation etched in a high-index substrate faces fabrication difficulties and an inherent contradiction preventing the achievement of both conditions of 100% transmission and of π phase difference between polarization components. The contradiction is solved by resorting to an easily fabricable high-index corrugation on a low-index substrate where a larger period gives rise to grating-mode reflection/transmission phases that permit the fulfillment of both conditions with a depth-minimized corrugation. From the principle of the solution, a targeted numerical search gives the complete set of the corresponding shallow structures, achieving polarization rotation in a fitting analytical form versus normalized variables.
authors: Université de Lyon, Laboratoire Hubert Curien, UMR CNRS 5516, Saint-Étienne, France. thomas.kampfe@univ‐st‐etienne.fr
authors: Thomas
authors: T
authors: Kämpfe
authors: Olivier
authors: O
authors: Parriaux