Abstract: This disclosure relates to a real-time, hybrid amplitude-time division polarimetric imaging camera used to derive and calculate Stokes parameters of input light.

Abstract: A switchable apochromatic polarization rotator is provided. A first fixed waveplate has a first principal axis fixed in a first orientation. A second fixed waveplate has a second principal axis fixed in a second orientation. First and second switchable waveplates have principal axes oriented such that broad spectral range electromagnetic radiation transmitted through all of the waveplates has a first rotated polarization, wherein, in response to one or more control signals applied to the switchable waveplates, the principal axes of the switchable waveplates rotate such that the electromagnetic radiation transmitted through all of the waveplates has a second rotated polarization. The switchable waveplates utilize ferroelectric liquid crystal material, nematic liquid crystal material, or be mechanically rotated to adjust for orientation of their principal axes. Utilizing waveplates as described may be used to tune for a desired spectral range and/or compensate for temperature dependencies.

Abstract: A switchable apochromatic polarization rotator is provided. A first fixed waveplate has a first principal axis fixed in a first orientation. A second fixed waveplate has a second principal axis fixed in a second orientation. First and second switchable waveplates have principal axes oriented such that broad spectral range electromagnetic radiation transmitted through all of the waveplates has a first rotated polarization, wherein, in response to one or more control signals applied to the switchable waveplates, the principal axes of the switchable waveplates rotate such that the electromagnetic radiation transmitted through all of the waveplates has a second rotated polarization. The switchable waveplates utilize ferroelectric liquid crystal material, nematic liquid crystal material, or be mechanically rotated to adjust for orientation of their principal axes. Utilizing waveplates as described may be used to tune for a desired spectral range and/or compensate for temperature dependencies.

Abstract: A dual field of view sighting system uses liquid crystals, flip-polarizers and/or flip-mirrors to select between at least two fields of view.

Abstract: A cadmium oxide (CdO) film doped with any of the Group III elements is substantially transparent to radiation between about 0.7 ?m and 12 ?m. A film made according to the invention having a sheet resistance of <600?/? will also have exceptionally low optical absorption throughout the IR range. The film is suitably employed as transparent, electrically conductive electrodes, and can be used in devices such as liquid crystal cells for beam steering, spatial light modulators, optical switches for fiber optical communications, switchable and/or tunable polarization modification components, and top transparent electrodes for SWIR (1.3 and 1.5 ?m) VCSELs.

Abstract: A spatial light modulator has a transmissive window with a transparent conductive film forming a ground plane and a direct drive backplane with a plurality of voltage gradient pixels. Each of the voltage gradient pixels has (a) resistive film, (b) resistive metal conductor frame on a boundary of the resistive film, and (c) conductive metal leads between a substrate of the direct drive backplane and the resistive metal frame. Differential voltages applied to the metal frame via the conductive metal leads generate a selective two-dimensional linear voltage gradient across the resistive film. A layer of liquid crystal material is disposed between the transmissive window and the voltage gradient pixels. Liquid crystal material of each voltage gradient pixel is responsive to an electric field generated by the voltage gradient to two-dimensionally alter phase of a wavefront incident thereon.

Abstract: An optical fiber coupling, for example, an optical switch, for coupling a light source with a light-receiving end face of an optical waveguide comprises a lens for focusing a light beam emitted from the light source at a focal point on the light-receiving end face of the optical waveguide. An adaptive coupler positioned in the optical path is responsive to a beam steering control signal for steering and aligning the focal point relative to the light-receiving end face of the optical waveguide.

Abstract: An optical fiber coupling, for example, an optical switch, for coupling a light source with a light-receiving end face of an optical waveguide comprises a lens for focusing a light beam emitted from the light source at a focal point on the light-receiving end face of the optical waveguide. An adaptive coupler positioned in the optical path is responsive to a beam steering control signal for steering and aligning the focal point relative to the light-receiving end face of the optical waveguide.

Abstract: An apparatus for optically coupling a light source with a light-receiving end face of an optical waveguide comprises a lens for focusing a light beam emitted from the light source at a focal point on the light-receiving end face of the optical waveguide. An adaptive coupler, positioned in the optical path, is responsive to a beam steering control signal for steering and aligning the focal point relative to the light-receiving end face of the optical waveguide. In one form, the adaptive coupler comprises a pair of transparent substrates having confronting, parallel inner faces, the inner face of one of the pair of substrates carrying a beam intercepting, optically transparent, constant potential electrode and the inner face of the other of the pair of substrates carrying an electrically resistive, beam intercepting, optically transparent film. A pair of spaced apart electrodes in electrical contact with the film apply a linear voltage gradient along the film.

Abstract: An apparatus for optically coupling a light source with a light-receiving end face of an optical waveguide comprises a lens for focusing a light beam emitted from the light source at a focal point on the light-receiving end face of the optical waveguide. An adaptive coupler, positioned in the optical path, is responsive to a beam steering control signal for steering and aligning the focal point relative to the light-receiving end face of the optical waveguide. In one form, the adaptive coupler comprises a pair of transparent substrates having confronting, parallel inner faces, the inner face of one of the pair of substrates carrying a beam intercepting, optically transparent, constant potential electrode and the inner face of the other of the pair of substrates carrying an electrically resistive, beam intercepting, optically transparent film. A pair of spaced apart electrodes in electrical contact with the film apply a linear voltage gradient along the film.

Abstract: The invention relates to an optical retardation film comprising a layer of an anisotropic polymer material with an optical axis substantially parallel to the plane of the layer. The invention furthermore relates to a process of preparing the optical retardation film, to the use of such an optical retardation film in liquid crystal displays, and to a liquid crystal display device comprising a liquid crystal cell and such an optical retardation film.

Abstract: An O-plate compensator is manufactured by dissolving a polyimide polymer material incorporating a plurality of bulky side-chain groups in a first solvent to form a first solution, applying the first solution to a substrate, evaporating the first solvent to form an alignment layer, buffing the alignment layer, dissolving a polymerizable liquid crystal material in a second solvent to form a second solution, applying the second solution to the alignment layer, evaporating the second solvent to form a thin film of polymerizable liquid crystal material (with a nematic phase, an alignment-layer interface having a liquid crystal pretilt angle of between approximately 25 and 65 degrees, and an air interface), adjusting the temperature of the thin film to obtain a uniform specified orientation of a director of the thin film, and polymerizing the thin film with ultraviolet radiation to achieve a liquid crystal pretilt angle of between approximately 25 and 65 degrees at the air interface.

Abstract: An electrical exciting circuit produces a plurality of oscillating electrical excitations, each at an independently controllable frequency. A set of drive electrodes are distributed in an array, and connected so that each receives a respective one of the excitations. A dual frequency liquid crystal (DFLC) material is arranged in the path of a coherent light beam and is disposed in proximity to the set of drive electrodes so as to receive electrical excitations. The DFLC has a dielectric coefficient which varies locally in relation to the frequency of the local electrical excitation received. The voltages and at least two frequencies of the excitations are controlled so as to produce a desired profile of the dielectric coefficient (for at least one polarization) and a corresponding optical phase delay profile for the coherent beam. Preferably, a novel reflective groundplane is included to improve optical reflective efficiency.

Abstract: An addressing scheme for use with current-driven emissive displays requires that an N-row by M-column array of pixels be divided into K segments of N/K rows each. One transistor-controlled current driver is provided for each column of pixels within a segment, and all of a segment's current drivers are connected to a respective gate address line. The array is addressed by dividing a frame time into N/K “sub-frame” times. During the first sub-frame time, the current drivers of each segment are turned on in sequence, and the first row of each segment addressed. The remaining rows are addressed in this manner during subsequent sub-frame times. The segmenting and addressing scheme reduces the duty ratio required to drive the array by a factor of K, and reduces the number of transistors required to drive the array by a factor of N/K, when compared with comparably-sized passive matrix and active matrix displays, respectively.

Abstract: An O-plate compensator comprising an organic liquid crystal polymer, and methods for fabricating the same, are disclosed. The compensator is a uniaxial birefringent thin film with its extraordinary axis oriented obliquely with respect to the surface of the film. (It is noted that the birefringent thin film could be weakly biaxial.) The oblique orientation of the liquid crystal director, which is parallel to the films extraordinary axis, is achieved by casting an organic thin film onto a surface specially prepared for a orienting liquid crystals, such as obliquely deposited SiO, mechanically rubbed alignment agents. The film can either be cast from a solution of the liquid crystal polymer or from a reactive liquid crystal monomer having a nematic phase. Any solvent that may be used during the fabrication process is evaporated off and the organic thin film is held at a temperature in its nematic phase. If a reactive monomer is used, the film is then photopolymerized.

Abstract: An assembly for restricting the angle of vision of an image emitted from an LCD screen comprising a linearly parallel arrangement of two polarizing films with at least two waveplates there between. The transmission planes of the polarizing films are at an angle, preferrably 90° to each other. At least two parallel waveplates are positioned between, the polarizing films. Each waveplate has parallel transmitting regions alternating between birefringent and isotropic regions. The waveplates are positioned in a spaced apart relationship to each other such that substantially orthogonal light passing through the first polarizing screen and one of the birefringent or isotropic alternating transmitting regions of the first waveplate will pass through the other of the alternating striped transmitting regions of the second waveplate. Light so transmitted will then pass through the second polarizing film and be viewable.

Abstract: The present invention relates to thin film retardation plates, such as cholesteric and A-plate compensators, for improving the viewing angle and contrast of liquid crystal displays. The A-plate is fabricated using a single substrate onto which a layer of polymerizable reactive mesogens (RMs) is solvent cast. Included in the RMs solution is an additive that migrates to the RM/air interface to lower the surface energy and generate an additive-rich surface layer, which in turn lowers the intrinsic tilt angle of the RMs at the air interface to between 25 degrees (25.degree.) and about zero degrees (0.degree.). The solvent is evaporated and the resulting film is polymerized in the liquid crystal phase to permanently orient the liquid crystal. The resulting film may be readily separated from the substrate and shaped into any desired pattern and combined to form novel compensators.

Abstract: An O-plate compensator comprising an organic liquid crystal polymer, and methods for fabricating the same, are disclosed. The compensator is a uniaxial birefringent thin film with its extraordinary axis oriented obliquely with respect to the surface of the film. (It is noted that the birefringent thin film could be weakly biaxial.) The oblique orientation of the liquid crystal director, which is parallel to the film's extraordinary axis, is achieved by casting an organic thin film onto a surface specially prepared for orienting liquid crystals, such as obliquely deposited SiO, mechanically rubbed alignment agents. The film can either be cast from a solution of the liquid crystal polymer or from a reactive liquid crystal monomer having a nematic phase. Any solvent that may be used during the fabrication process is evaporated off and the organic thin film is held at a temperature in its nematic phase. If a reactive monomer is used, the film is then photopolymerized.

Abstract: A normally white liquid crystal display includes polarizer and analyzer layers having perpendicular absorbing axes. A liquid crystal layer is disposed between the polarizer layer and the analyzer layer, with its director exhibiting an azimuthal twist through the layer. First and second electrodes are proximate to first and second major surfaces of the liquid crystal layer. A first negatively birefringent compensator layer, oriented with its optical axis substantially parallel to the average direction of the optical axis within a central, nominally homeotropic region of the liquid crystal layer in its driven state, is disposed between the polarizer layer and the liquid crystal layer. A second negatively birefringent compensator layer, with a birefringence substantially the same as the birefringence of the first compensator layer and oriented with its optical axis substantially parallel to the optical axis of the first compensator layer, is disposed between the analyzer layer and the liquid crystal layer.

Abstract: A normally white super-twist nematic liquid crystal display is disclosed. Between a polarizer layer and an analyzer layer, the display includes a super-twist nematic liquid crystal cell having first and second substrates and a liquid crystal layer disposed between the first and second substrates. The display further includes at least one positively birefringent A-plate compensator layer disposed between the polarizer layer and the super-twist nematic liquid crystal cell and at least one positively birefringent A-plate compensator layer disposed between the analyzer layer and the super-twist nematic liquid crystal cell to reduce chromaticity shifts of the display at wide viewing angles and over temperature variations.