Abstract: A retarder including first and second outer layers and a birefringent layer disposed between and in direct contact with the first and second outer layers is described. The birefringent layer may include a first polyester having greater than 45 mole percent naphthalate units and greater than 45 mole percent ethylene units. Each of the first and second outer layers includes a second polyester which may include 40 to 50 mole percent naphthalate units, at least 25 mole percent ethylene units, and 10 to 25 mole percent of branched or cyclic C4-C10 alkyl units. The retarder has a retardance in a range of 1 micrometer to 100 micrometers.

Abstract: Provided is an anisotropic optical film, which can, while keeping excellent display characteristics (e.g., brightness and contrast) in the direction of a viewing angle, suppress decreased display characteristics in the other directions, when the anisotropic optical film is used as a diffusion film of a display panel.

Abstract: A birefringent Mach-Zehnder interferometer (MZI) is provided for optically sensing a small fluctuation from an un-polarized light beam. The birefringent MZI includes first and second birefringent crystals arranged coaxially, the first crystal to receive the beam; and first and second 45° polarizers positioned behind respective the first and second crystals. The first crystal divides the beam into first ordinary and extraordinary rays. The first polarizer converts the first rays into first 45° rays. The second crystal divides the first 45° rays into second ordinary, extraordinary and recombination rays. The second polarizer converts the second rays into second 45° rays.

Abstract: Thermochromic filters use combinations of absorptive, reflective, thermoabsorptive, and thermoreflective elements covering different portions of the solar spectrum, to achieve different levels of energy savings, throw, shading, visible light transmission, and comfort. Embodiments include stopband filters in the near-infrared spectrum.

Abstract: Imaging optics having reduced susceptibility to thermally-induced stress birefringence for imaging an object plane to an image plane; comprising an aperture stop positioned between the object plane and the image plane; a first group of optical elements located on the object plane side of the aperture stop; and a second group of optical elements located on the image plane side of the aperture stop. The optical elements in the first and second groups that are immediately adjacent to the aperture stop are refractive lens elements fabricated using optical materials having a negligible susceptibility to thermal stress birefringence, and the other optical elements are a combination of reflective optical elements and refractive lens elements fabricated using optical materials having at most a moderate susceptibility to thermal stress birefringence.

Abstract: A thermochromic smart window and a method of manufacturing the thermochromic smart window including a glass and a thermochromic layer including a vanadium dioxide material formed on the glass. A thermochromic smart window includes a substrate and a thermochromic layer disposed on the substrate, wherein a slope of a graph of a reflectance of the thermochromic layer is at or between 1 and 2%/° C. at a threshold temperature.

Abstract: An optical device to reduce the thermally induced distortion and thermally induced depolarization of light transmitted through all or part of the device. The device includes a nominally transparent element having a negative dn/dT and a nominally transparent element having a zero or negative stress optic coefficient.