Abstract: The invention includes an apparatus for processing an input optical beam. The apparatus has at least one variable optical element to dynamically alter the polarization state of an optical beam to form a polarization-altered optical beam, wherein the polarization-altered optical beam includes elliptical polarization. At least one wave plate operates on the polarization-altered optical beam, each wave plate has a selected retardation, order of retardation, and orientation. A polarization analyzer, operating in conjunction with the at least one variable optical element and wave plate, alters the transmitted amplitude of the polarization-altered optical beam as a function of wavelength, and thereby produces an output optical beam with transmitted amplitude adjusted as a function of wavelength.

Abstract: A useful optical device to provide continuously variable rotation of polarization of linearly polarized light in a wavelength-independent manner. This device features a cell of twisted nematic liquid crystal sandwiched between an input window and a rotatable output window, both with surfaces prepared so as to orient the nematic liquid crystal molecules. This optical device has different applications such as: variable-angle polarization rotator; using broad band polarizers as an energy attenuator; working in both cases as a wavelength independent and temporal pulse width independent device. The low cost, the very wide field of view, the wavelength and pulse width independence, the high efficiency, and its mechanical simplicity make of this new optical device a very useful and novel invention.

Abstract: The invention relates to a head-mounted display provided with an image display device and an optical system. The optical system comprises a first &lgr;/4 plate, a semi-transmissive mirror, a second &lgr;/4 plate and a polarization-dependent mirror, disposed in the described order from the incident side, for projecting an image to be formed by the image display device on a user's retina.

Abstract: An electro-optical device is provided having a structure which, in particular, allows the device to be made smaller and thinner, and the heat-dissipation capability to be increased in order to prevent overheating. A positioning section which accommodates an opposing substrate, and which contacts an edge of an element substrate is provided in a case member accommodating an electro-optical panel which consists of the opposing substrate and the element substrate.

Abstract: A method for stretching an optical polymer film is described, which comprises allowing a locus L1 of the holding means from a substantial holding initiation point to a substantial holding release point on one edge of the polymer film, a locus L2 of the holding means from a substantial holding initiation point to a substantial holding release point on the other edge of the polymer film, and a distance W between the two substantial holding release points to satisfy the following equation (1), maintaining the supporting property of the polymer film, stretching the film in the presence of a state in which the volatile content is 5% or more, and then, decreasing the volatile content while shrinking the film:

Abstract: A polarizing member has a reflection type polarizing plate capable of separating natural incident light into reflected light and transmitted light to thereby obtain polarized transmitted light, and a fine concave-convex structure disposed on a single surface of the reflection type polarizing plate. The fine concave-convex structure has a center-line average roughness Ra of from 0.01 to 0.1 &mgr;m, ten or more convex portions with a height of from 0.5 to 1.0 &mgr;m, and two or less convex portions with a height larger than 1.0 &mgr;m on any 1 mm-long line segment, and the fine concave-convex structure has a surface hardness of from H to 4H in terms of pencil hardness.

Abstract: A dynamic gain flattening filter includes a first filter stage. The first filter stage has a first tunable coupling member and a first differential delay with first and second tunable delay paths. The first tunable coupling member adjusts an amount of power of the optical signal that is divided onto the first and second tunable delay paths of the first differential delay.

Abstract: A reconfigurable bi-directional wavelength selective switch is disclosed. It has an optical system that is symmetric about a polarization modulator. The symmetric optical system consists of an input birefringent optical system and output birefringent optical system disposed around polarization modulator. The optical system delivers the wavelength channels that are to be switched as a superimposed wavelength channel incident the polarization modulator. As a result, crosstalk is reduced below −35 dB and greater optical performance is achieved.

Abstract: The object to be identified is affixed with an identification medium comprising a reflective layer consisting of a reflective hologram or diffraction grating. The high polymer cholesteric liquid crystal provides an inexpensive identification medium, and the use of the second light receiving unit for providing a reference signal provides a high S/N output signal which is highly distinct and resistant to the contamination of the identification medium. Also, the elimination of the need for expensive optical elements such as beam splitters also contributes to the reduction of cost.

Abstract: The present invention,is directed to an optical space switch accommodating a plurality of input light paths and output light paths. The optical space switch comprises a plurality of polarization control optical switches, each consisting essentially of: polarization control means having elements, one for each input light path, for rotating through 90° the polarizing direction of light information incident from each input light path or otherwise retaining the polarizing direction thereof for output; and a light path routing element for routing the light path for the light information output from the polarization control means in accordance with the polarizing direction of the light information. These polarization control optical switches are arranged in a matrix pattern or coupled in cascade to implement a polarization control optical space switch.

Abstract: A polarization device includes a reflection-type polarization element disposed at a side to which an optical beam comes in and an absorption-type polarization element disposed behind the reflection-type polarization element, wherein the reflection-type polarization element and the absorption-type polarization element are disposed such that a transmission axis of the reflection-type polarization element coincides with the transmission axis of the absorption-type polarization element. Further, an optical projector using such a polarization device is disclosed.

Abstract: A polarizer is described that is formed of a host matrix and a guest dye. The host matrix may be a lyotropic liquid crystal matrix having a predetermined orientation. A guest pleochroic dye may be disposed within the host lyotropic liquid crystal matrix. The guest pleochroic dye is oriented by the orientation of the host matrix.

Abstract: Disclosed are super broadband circularly polarizing film materials and novel methods of fabricating and using the same. The circularly polarizing materials are made from polymerizable CLC film material having a cholesteric order, in which a liquid crystal material, such as a nematic liquid crystal material, is distributed in a non-linear fashion across the thickness of the film in a plurality of liquid crystal-rich and liquid crystal-depleted sites in the CLC polymer. The pitch of the helices of the CLC molecules in the polyermized CLC material varies in a non-linear (e.g. exponential) manner along the depth dimension (i.e. transverse to the surface) thereof. The resulting circularly polarizing materials have reflection and transmission characteristics over bands of operation approaching 2000 nm. Depending on the final spiral structure of the polymeriable CLC materials utilized, the CLC circularly polarizing materials reflect either left-handed or right-handed circularly polarized light.

Abstract: A polarization luminaire of the present invention has a light source, an optical integrator, a polarized light splitting means and a polarization conversion means. The polarized light splitting means splits a light emitted from the light source into two kinds of polarized lights. The polarization directions of the two kinds of polarized lights are perpendicular to each other and travel in directions separated by an angle of less than 90 degrees. The polarization conversion means modifies the two kinds of polarized lights to have the same polarization direction. The polarized light splitting means is placed on the entrance side or the outputting side of a first lens plate of the optical integrator, or is placed within a second lens plate. A prism beam splitter having a polarized light splitting film that includes a thermally stable dielectric multi-layer film may be used as the polarized light splitting means.

Abstract: The present invention is directed to an optical space switch accommodating a plurality of input light paths and output light paths. The optical space switch comprises a plurality of polarization control optical switches, each consisting essentially of: polarization control means having elements, one for each input light path, for rotating through 90.degree. the polarizing direction of light information incident from each input light path or otherwise retaining the polarizing direction thereof for output; and a light path routing element for routing the light path for the light information output from the polarization control means in accordance with the polarizing direction of the light information. These polarization control optical switches are arranged in a matrix pattern or coupled in cascade to implement a polarization control optical space switch.

Abstract: A polarization device includes a reflection-type polarization element disposed at a side to which an optical beam comes in and an absorption-type polarization element disposed behind the reflection-type polarization element, wherein the reflection-type polarization element and the absorption-type polarization element are disposed such that a transmission axis of the reflection-type polarization element coincides with the transmission axis of the absorption-type polarization element. Further, an optical projector using such a polarization device is disclosed.

Abstract: Process for broadening cholesteric reflection bands of photopolymerizable cholesteric liquid crystals, and optical elements produced by this process. The invention relates to a process for broadening the cholesteric reflection bands of photopolymerizable cholesteric liquid crystals, which comprises the following process steps:1) partial polymerization of a layer containing photopolymerizable cholesteric liquid crystals by exposure to actinic light for a defined brief period at a defined temperature,2) observance of a defined waiting time without exposure (dark phase) at a defined temperature,3) fixing of the resultant layer by exposure to actinic light at a defined temperature.

Abstract: A polarized-light converting elemental device which can produce an accurately unidirectionally and circularly polarized light with a minimized loss of light and a projection-type display device using said unidirectionally-polarized-light converting elemental device are provided. A polarized-light converting elemental device comprises a mirror glass portion consisting of an array of mirror glass blocks each having a first reflecting optical element and a second reflecting optical element and a cholesteric-liquid-crystal glass portion including a cholesteric liquid crystal layer for reflecting either clockwise circularly polarized component or anticlockwise circularly polarized component and transmitting the other. Natural light from the left side is split into two directions by the first reflecting optical element. Light reflected from the cholesteric liquid crystal is reflected by the second reflecting optical element to alter its rotation direction and then transmitted through the cholesteric liquid crystal.

Abstract: Disclosed are super broadband circularly polarizing film materials and novels methods of fabricating and using the same. The circularly polarizing materials are made from polymerizable CLC film material having a cholesteric order, in which a liquid crystal material, such as a nematic liquid crystal material, is distributed in a non-linear fashion across the thickness of the film in a plurality of liquid crystal-rich and liquid crystal-depleted sites in the CLC polymer. The pitch of the helices of the CLC molecules in the polyermized CLC material varies in a non-linear (e.g. exponential) manner along the depth dimension (i.e. transverse to the surface) thereof. The resulting circularly polarizing materials have reflection and transmission characteristics over bands of operation approaching 2000 nm. Depending on the final spiral structure of the polymerizable CLC materials utilized, the CLC circularly polarizing materials reflect either left-handed or right-handed circularly polarized light.

Abstract: An optical polarizer including a polarizing beam splitter including first and second transparent elements separated by a layer of a birefringent material, the layer of the birefringent material being operative to change the polarity of light passing therethrough, the polarizing beam splitter being operative to receive a beam of unpolarized light at the first transparent element, to cause a first beam of light of a first polarity to undergo total internal reflection at an interface between the first transparent element and the layer of birefringent material and to pass a second beam of light of a second polarity through the layer of birefringent material, thus changing its polarity to the first polarity, a first reflector associated with a quarter wave plate and being arranged to receive the first beam of light of a first polarity reflected from the interface between the first transparent element and the layer of a birefringent material via the first transparent element and to change the polarity of the light

Abstract: An illumination system (3) comprises an optical waveguide (9) of an optically transparent material having an exit surface (19) and four end faces (13, 14, 15, 16). The light from a light source (11) is coupled into the optical waveguide (9) via at least one of the end faces (13). The illumination system, for an LCD, further has a reflective polarizer (21) in combination with a diffuser (23) for polarizing the light supplied by the light source (11). The reflective polarizer (21) is integrated with the optical waveguide and constitutes the surface (25) of the optical waveguide (9) which is located opposite the exit surface (19). The diffuser (23) is present on a surface of the polarizer (21) remote from the optical waveguide (9).

Abstract: A film of photosensitive material is illuminated from first and second sides with coherent polarized light so as to form an interference pattern within the film. Regions of cyclicly varying refractive index are provided in the film in accordance with the intensity of the interference patten, thereby forming an polarization sensitive refractive index grating. The refractive index grating may be used as a polarization and wavelength dependent mirror, patterned polarizer, beamsplitter or filter.

Abstract: An illumination system comprising a reflector, a cholesteric filter and a depolarizer. The cholesteric filter is arranged between a radiation source and, in a display device, a display panel, and is selected to transmit radiation having a selected state of polarization in a selected wavelength range, while reflecting otherwise polarized radiation in that wavelength range. The depolarizer is disposed between the reflector and the cholesteric filter. Radiation reflected by the cholesteric filter is re-reflected to the filter by the reflector and, having been depolarized in the depolarizer, is transmitted to the extent it has the selected state of polarization in the selected wavelength.

Abstract: The present invention relates generally to broadband, reflective circular polarizers and, more particularly, to single layer super broadband, reflective circular polarizers. The polarizers of the present invention are made from a film of material, like a polymer having a cholesteric order, in which a second liquid crystal material, like a nematic liquid crystal, is distributed in a non-linear fashion across the thickness of the film in a plurality of liquid crystal-rich and liquid crystal-depleted sites in the polymer. The resulting polarizers have band passes approaching 2000 nm and reflect circularly polarized light which is either left-handed or right-handed depending on the final spiral structure of the materials utilized. The material of the present invention is fabricated by mixing commercially available polymers having a cholesteric order, a second liquid crystal material and a photoinitiator at a temperature which maintains the mixture in a liquid state.

Abstract: A polarel panel includes a sheet polarizer in intimate juxtaposition with a layer made up of regions of isotropic material interspersed with regions of liquid crystal material. In one embodiment, optical activity of the liquid crystal material rotates the electric vector of incoming linearly polarized light through 90.degree. in selected areas. In another embodiment, birefringence causes rotation of the electric vector of incoming linearly polarized light through 90.degree. in selected areas.

Abstract: This invention provides a liquid crystal polarization handedness switch, and optical devices employing the handedness switch in conjunction with optical elements which are sensitive to the handedness of incident light. The handedness switch receives unpolarized light and converts it into circularly polarized light with switchable handedness. In combination with cholesteric circular polarizers, switchable color filters are provided. The color filters of this invention include the analogous x-y polarization switch combined with colored partial polarizers. The liquid crystals employed in the color filter of this invention can include SmC*, SmA*, antiferroelectric, DHF, achiral ferroelectric and twisted nematic liquid crystals.

Abstract: The liquid crystal light modulation device of the present invention comprising a liquid crystal element consisting of one of plural liquid crystal cells and a voltage signal input means electrically connected with the liquid crystal element, wherein each liquid crystal cell contains a chiral smectic liquid crystal material layer and when a voltage signal is input to the liquid crystal element, the polarization direction of a light transmitted by the liquid crystal element is changed by approx. 90.degree. as compared with the state where the voltage signal is not input to the liquid crystal element enables a change of a light path and an open-close (on-off) operation of a light path at a high speed (optical switching time: not longer than 1 msec).