Abstract: A method for producing a photostable reactive mesogen alignment layer includes infusing an anisotropic dye into a microcavity so as to coat the an surface of the microcavity with the anisotropic dye; illuminating the anisotropic dye with polarized light so as to form an anisotropic dye layer aligned with respect to the inner surface of the microcavity; infusing a reactive mesogen and the liquid crystal material into the microcavity; illuminating the reactive mesogen at a wavelength selected to cause polymerization of the layer of the reactive mesogen so as to form a polymerized reactive mesogen layer; aligning the liquid crystal material with respect to the anisotropic dye layer; and bleaching the anisotropic dye layer.

Abstract: Liquid crystal photonic devices and microcavities filled with liquid crystal materials are becoming increasingly popular. These devices often present a challenge when it comes to creating a robust alignment layer in pre-assembled cells. Previous research on photo-definable alignment layers has shown that they have limited stability, particularly against subsequent light exposure. A method of infusing a dye into a microcavity to produce an effective photo-definable alignment layer is described, along with a method of utilizing a pre-polymer infused into the microcavity mixed with the liquid crystal to provide photostability. In this method, the polymer layer, formed under optical irradiation of liquid crystal cells, is effectively localized to a thin region near the substrate surface and thus provides a significant improvement in the photostability of the liquid crystal alignment.

Abstract: Liquid crystal photonic devices and microcavities filled with liquid crystal materials are becoming increasingly popular. These devices often present a challenge when it comes to creating a robust alignment layer in pre-assembled cells. Previous research on photo-definable alignment layers has shown that they have limited stability, particularly against subsequent light exposure. A method of infusing a dye into a microcavity to produce an effective photo-definable alignment layer is described, along with a method of utilizing a pre-polymer infused into the microcavity mixed with the liquid crystal to provide photostability. In this method, the polymer layer, formed under optical irradiation of liquid crystal cells, is effectively localized to a thin region near the substrate surface and thus provides a significant improvement in the photostability of the liquid crystal alignment.

Abstract: Liquid crystal photonic devices and microcavities filled with liquid crystal materials are becoming increasingly popular. These devices often present a challenge when it comes to creating a robust alignment layer in pre-assembled cells. Previous research on photo-definable alignment layers has shown that they have limited stability, particularly against subsequent light exposure. A method of infusing a dye into a microcavity to produce an effective photo-definable alignment layer is described, along with a method of utilizing a pre-polymer infused into the microcavity mixed with the liquid crystal to provide photostability. In this method, the polymer layer, formed under optical irradiation of liquid crystal cells, is effectively localized to a thin region near the substrate surface and thus provides a significant improvement in the photostability of the liquid crystal alignment.

Abstract: A phase retarder comprises first and second ?-cells or other tunable birefringent devices arranged optically in series. The phase retardation value of the phase retarder is a difference between the phase retardation values of the first and second ?-cells. Driving circuitry drives the phase retarder to generate a target phase retardation value by: (1) prior to a relaxation period, biasing the ?-cells to produce the target phase retardation value; (2) during the relaxation period, biasing the first ?-cell at a constant bias value; and (3) during the relaxation period, lowering the bias value of the second ?-cell continuously or stepwise to maintain the target phase retardation value for the phase retarder throughout the relaxation period. In some embodiments the operation (2) comprises applying zero bias to the first ?-cell throughout the relaxation period. In some embodiments the operation (1) comprises applying a maximum operational bias to the second ?-cell.

Abstract: A phase retarder comprises first and second ?-cells or other tunable birefringent devices arranged optically in series. The phase retardation value of the phase retarder is a difference between the phase retardation values of the first and second ?-cells. Driving circuitry drives the phase retarder to generate a target phase retardation value by: (1) prior to a relaxation period, biasing the ?-cells to produce the target phase retardation value; (2) during the relaxation period, biasing the first ?-cell at a constant bias value; and (3) during the relaxation period, lowering the bias value of the second ?-cell continuously or stepwise to maintain the target phase retardation value for the phase retarder throughout the relaxation period. In some embodiments the operation (2) comprises applying zero bias to the first ?-cell throughout the relaxation period. In some embodiments the operation (1) comprises applying a maximum operational bias to the second ?-cell.

Abstract: An electro-optical device comprises a liquid crystal material disposed in a cell and electrodes configured to bias the liquid crystal material into a generally in-plane director configuration having a non-constant spatial pattern selectable or adjustable by an in-plane component of the biasing to produce a desired refractive of diffractive optical effect.

Abstract: Provided is a liquid crystal (LC) device and method thereof. The device comprises (i) a body of liquid crystal, (ii) a first layer comprising a first material, and (iii) a second layer comprising a second material; wherein the first layer is located between the body of liquid crystal and the second layer; the first layer alone aligns the liquid crystal in a first orientation; the second layer alone aligns the liquid crystal in a second orientation; and the first orientation is different from the second orientation. With optimized first layer thickness, the invention can be used in sensor applications to improve detection sensitivity, and in LCD applications with enhanced control over LC pretilt transition.

Abstract: A liquid crystal etalon includes a chiral nematic material contained in a liquid crystal cell having alignment surfaces configured to bias the chiral nematic material toward a twisted liquid crystal configuration with a twist less than 360°. Electrodes are arranged to apply an operative electrical bias to the liquid crystal cell. Mirrors disposed about the chiral nematic material define a resonant optical cavity. At a first electrical bias the etalon is transmissive for light of a first wavelength via a selected liquid crystal twist angle and cavity thickness at which different non-equal eigenmodes reach resonance conditions simultaneously. In a projector embodiment, a projection system with a field sequential image projection light source is coupled with the liquid crystal etalon, the etalon electrodes are patterned into pixels defining a display area, and the projector is operated in a field sequential illumination mode.

Abstract: The present invention relates to a liquid crystal alignment agent, a liquid crystal device produced by using the liquid crystal alignment agent thereof, and a method for alignment of liquid crystal molecules by using the liquid crystal alignment agent. In more detail, the present embodiments relates to a novel liquid crystal alignment agent used in a method of aligning liquid crystal molecules, wherein the agent includes a molecule having a highly polar functional group grafted onto an end of the molecule.

Abstract: Provided is a liquid crystal (LC) device and method thereof. The device comprises (i) a body of liquid crystal, (ii) a first layer comprising a first material, and (iii) a second layer comprising a second material; wherein the first layer is located between the body of liquid crystal and the second layer; the first layer alone aligns the liquid crystal in a first orientation; the second layer alone aligns the liquid crystal in a second orientation; and the first orientation is different from the second orientation. With optimized first layer thickness, the invention can be used in sensor applications to improve detection sensitivity, and in LCD applications with enhanced control over LC pretilt transition.

Abstract: A liquid crystal etalon includes a chiral nematic material contained in a liquid crystal cell having alignment surfaces configured to bias the chiral nematic material toward a twisted liquid crystal configuration with a twist less than 360°. Electrodes are arranged to apply an operative electrical bias to the liquid crystal cell. Mirrors disposed about the chiral nematic material define a resonant optical cavity. At a first electrical bias the etalon is transmissive for light of a first wavelength via a selected liquid crystal twist angle and cavity thickness at which different non-equal eigenmodes reach resonance conditions simultaneously. In a projector embodiment, a projection system with a field sequential image projection light source is coupled with the liquid crystal etalon, the etalon electrodes are patterned into pixels defining a display area, and the projector is operated in a field sequential illumination mode.

Abstract: An electro-optical device comprises a liquid crystal material disposed in a cell and electrodes configured to bias the liquid crystal material into a generally in-plane director configuration having a non-constant spatial pattern selectable or adjustable by an in-plane component of the biasing to produce a desired refractive of diffractive optical effect.

Abstract: A liquid crystal display device including a polyimide alignment layer, having a bistable liquid crystal material and a polymer stabilizer in an amount effective to stabilize the liquid crystal the liquid crystal preferably having a low or medium pretilt angle to eliminate undesired states and stripe tendency and to increase hysteresis. The device has a low driving voltage, low power consumption and fast switching.

Abstract: A driving circuit for a reflective bistable cholesteric liquid crystal display which includes one substrate having a plurality of column or segment electrodes opposed by another substrate having a plurality of row or common electrodes. The intersecting column and row electrodes with the cholesteric material therebetween form a plurality of pixels. The driving circuit selectively applies a voltage to the row and column electrodes to control the appearance of the cholesteric material. In particular, the driving circuit includes at least one common driver coupled to respective common electrodes with each common driver having a first and a second common frame switch with corresponding high or low inputs. The first and second common frame switches are linked to one another by a common frame line.

Abstract: A liquid crystalline light modulating pixel includes first and second cell wall structures and nematic liquid crystal disposed therebetween. The first and second cell wall structures cooperate with the liquid crystal to form four liquid crystal domains within the pixel. The liquid crystal in each of the domains exhibits a twisted nematic liquid crystal structure and the orientation of the liquid crystal director of the liquid crystal adjacent one of the cell wall structures in at least two domains is different.

Abstract: A liquid crystal display device including a polyimide alignment layer, having a bistable liquid crystal material and a polymer stabilizer in an amount effective to stabilize the liquid crystal, preferably about 2 weight percent, associated with the liquid crystal material, the liquid crystal having a low pretilt angle, to eliminate stripe tendency and to increase hysteresis. The device has a low driving voltage, low power consumption and fast switching.

Abstract: A liquid crystalline light modulating pixel includes first and second cell wall structures and nematic liquid crystal within a UV cured polymer network disposed therebetween. The first and second cell wall structures cooperate with the liquid crystal to form four liquid crystal domains within the pixel. The liquid crystal in each of the domains exhibits a twisted nematic liquid crystal structure and the orientation of the liquid crystal director of the liquid crystal adjacent one of the cell wall structures in at least two domains is different. The polymer network stabilizes the four domain structure at both high field and zero field conditions.

Abstract: A reflective liquid crystalline diffractive light valve for use in a diffractive projection system. The liquid crystal cell includes a transparent substrate and a reflective substrate treated to provide alternating stripes which cooperate with the liquid crystal to form liquid crystal domains extending across the thickness of the cell that will produce an appropriate phase difference in light reflected by the cell, irrespective of the polarization of incident light. The techniques embodied in the present invention are applicable to the creation of electrically controllable diffractive optical elements for ray optic, integrated optic or fiber optic utilization operated in either transmission or reflection. Diffractive patterns may be lithographically, holographically or interferometrically generated.

Abstract: A method for forming a uniformly-spaced plastic substrate liquid crystal cell (100) includes the step of forming a cell with a liquid crystal-monomer mixture (150) disposed between upper and lower plastic substrates (111, 112). The cell (100) is then exposed to ultraviolet light (170) causing the monomer to be selectively polymerized to form support walls (108) between substrates (111, 112) of the cell in the light-intense areas. The monomer may be selectively polymerized by exposing the cell (100) through a mask (180, 188). The distance between the substrates (111, 112) is maintained before the walls (108) are formed by dispersing plastic ball spacers (114) between the substrates (111, 112). During exposure to the UV light, the substrates (111, 112) are sandwiched between substantially planar supports (182, 184) to maintain contact between the substrates (111, 112) and the spacers (114) and thus a uniform distance between the substrates (111, 112).