Phase retarders in liquid crystals polymers

Liquid crystals polymers posses birefringent properties and they are locally orientable, they allow the realization of space variant optical retarders which creates non uniformly polarized beam. To realize a retarder, liquid crystals are exposed to a UV linearly polarized beam, the optical axis of the retarder will be parallel to the incident polarization. We shall present an innovative way to produce space-variant retarders without mechanical interaction polarization holography . Superposing several beams differently polarized, results in a non-uniformly polarized recording beam used to realize space variant retarders. We shall also present our research retarders for two applications based on this method polarization analysis and coronagraphy.