Space-variant polarization state manipulation with computer-generated subwavelength metal stripe gratings

A novel approach to the design and analysis of space-variant polarization elements using computer-generated subwavelength metal stripe gratings is presented. We demonstrate that by locally controlling the direction and period of the grating any desired space-variant polarization state manipulation can be obtained. We illustrate our approach with two distinct types of manipulators: space-variant polarizers and space-variant polarization state transformations. The elements were formed on GaAs as well as ZnSe substrates and designed for laser radiation at 10.6 mum. The results include full space-variant polarization calculations and measurements and show high-quality space-variant polarized beams with a polarization purity of over 99%. (C) 2001 Published by Elsevier Science B.V.