Simple techniques to generate binary periodical polarization fields.

We report two new, to the best of our knowledge, methods to generate polarization gratings, whose basic cells are formed by sections that are orthogonally polarized. One of the methods employs a spatial filtering setup that modulates the diffraction orders in the Fourier domain of a Ronchi grating, with two orthogonal polarizations. In the second method, a binary phase modulation, generated by a liquid crystal device, is converted into orthogonal polarizations in different zones of an incident beam.