Arbitrary spatially variant polarization by unitary transformations in a common path interferometer

Abstract

We introduce a novel, common path interferometric technique, for generating hybrid spatially variant polarized fields and Poincare beams. The technique is based on unitary polarization transformations employing a single spatial light modulator in a Sagnac-like common path interferometer. This technique allows generating arbitrary fields as a superposition of orthogonal elliptically polarized vortex basis with opposite handedness. We demonstrate the generation of such fields theoretically and verify it experimentally for azimuthal and spiral polarization. As an example of application, we generated a radially polarized ring-shaped field and characterize it by Stokes polarimetry.