Abstract: An optical switch is provided in which a cell comprised of photopolymer dispersed in a liquid crystal sandwiched between two transparent plates is first recorded with a grating utilizing two plane wave laser beams interacting at an angle. This grating is permanently established in the cell such that when the cell is illuminated the incoming beam is diffracted in accordance with the spatial frequency of the grating. When an electric signal is applied across the cell, the refractive index of the liquid crystal matches that of the photopolymer due to the molecular orientation of the liquid crystal and no diffraction occurs because the grating formed in the liquid crystal is temporarily erased or over written. The liquid crystal cell therefore becomes transparent with the application of the electrical signal. Switching occurs by whether or not the grating is present or not, which is in turn dependent upon whether or not there is an electrical signal applied across the cell.

Abstract: Liquid crystal devices are formed by a layer of a liquid crystal material enclosed between two cell walls, both carrying electrode structures, and one or both walls treated to align molecules of the liquid crystal material. Most alignment treatment give alignment and surface pretilt with a strong azimuthal and zenithal anchoring energy to contacting liquid crystal molecules. The invention reduces at least one of the azimuthal zenithal or translational anchoring energy to improve switching characteristics and optical performance by allowing movement of liquid crystal molecules at or close to the cell wall. The reduction of anchoring energy may be achieved by an oligomer or short chain polymer which is either spread on the surface or added to the liquid crystal material. The size of oligomer or short chain polymer is low enough that it does not appreciably phase separate from the liquid crystal material.

Abstract: A spatially modulated interferometer incorporates a beam shearing system having a plurality of reflective surfaces defining separate light paths of equal optical path length for two separate output beams. The reflective surfaces are arranged such that when the two beams emerge from the beam shearing system they contain more than 50 percent of the photon flux within the selected spectral pass band. In one embodiment, the reflective surfaces are located on a number of prism elements combined to form a beam shearing prism structure. The interferometer utilizing the beam sharing system of the invention includes fore-optics for collecting light and focusing it into a beam to be sheared, and a detector located at an exit pupil of the device. In a preferred embodiment, the interferometer has no moving parts.

Abstract: A liquid crystal display (LCD) device having a color filter on a thin film transistor (TFT) structure (COT structure). The color filter layers are formed on the same substrate as the TFT to be in direct contact with the source and drain electrodes without any intermediaries therebetween. In particular, there is no need for a passivation layer between the TFT and the color filter layers. Preferred embodiments include a back etched type TFT that does not require a light shielding layer, an etch-stopped type TFT having an etch stop layer, and a coplanar type TFT having a light shielding layer below the gate electrode of the TFT.