Abstract: A method and apparatus for instantaneous measurement of the complete state of polarization across an image. A polarimetric encoding scheme is employed to uniquely map the spatially-varying state of polarization across a partially-polarized image to irradiance variations in a polarization-encoded interference pattern. In one embodiment of the method, two spatially-varying retarders and a linear polarizer comprise an interferometric polarization interrogating filter assembly. When a conventional irradiance image is presented to the filter assembly, it is decomposed into polarized and unpolarized components. While the unpolarized component passes through the filter substantially unaffected, the polarized component gives rise to a polarization-encoded interference pattern that overlaps the scene so that local regions within the image having specific polarization content may be recognized.

Abstract: A method and apparatus for instantaneous measurement of the complete state of polarization across an image. A polarimetric encoding scheme is employed to uniquely map the spatially-varying state of polarization across a partially-polarized image to irradiance variations in a polarization-encoded interference pattern. In one embodiment of the method, two spatially-varying retarders and a linear polarizer comprise an interferometric polarization interrogating filter assembly. When a conventional irradiance image is presented to the filter assembly, it is decomposed into polarized and unpolarized components. While the unpolarized component passes through the filter substantially unaffected, the polarized component gives rise to a M polarization-encoded interference pattern that overlaps the scene so that local regions within the image having specific polarization content may be recognized.

Abstract: An improvement in a method of rotating the plane of polarization of polarized light in a Faraday rotator, having an optical element which includes a ferromagnetic material, which comprises varying the strength of the magnetic field generated along the optical axis of the optical element in response to changes in the wavelength of the polarized light. The magnet employed in the Faraday rotator may be at least one permanent magnet or an electromagnet. Preferred optical elements are made of disc having a gadolinium-gallium-garnet (GGG) or large lattice constant (LLC) substrate, and the substrate is coated with an oxygen--and iron--containing film.