320results about How to "Low birefringence" patented technology

An optical article made of a transparent polymer which includes terephthaloyl moieties, optionally, other aromatic diacid moieties; ethylene glycol moieties; isosorbide moieties; and, optionally, one or more other diol moieties, wherein the polymer has an inherent viscosity of at least about 0.35 dL/g as measured on a 1% solution (weight/volume) in o-chlorophenol at 25 DEG C.

Fused silica members having high internal transmission and low birefringence are disclosed. Methods of making such fused silica members are also disclosed. According to the present invention, fused silica members having an internal transmission equal to or greater than 99.65%/cm at 193 nm and having an absolute maximum birefringence along the use axis of less than or equal to 0.75 nm/cm are provided.

An optical power beam transmission systems, with a directional light transmitter and receiver. The transmitter contains an amplifying laser medium, and this together with a retroreflector in the receiver, forms a laser resonator. When lasing sets in, the receiver can extract optical power through an output coupler and convert it to electrical power. The gain medium may be a disc having a thickness substantially smaller than its lateral dimensions. The laser resonator is operated as a stable resonator to ensure safe operation. This is achieved by use of an adaptive optical element, for reducing the diameter of the energy beam impinging on the gain medium, thereby increasing the overlap between the energy beam and the gain medium. As the transmitter-receiver distance is changed, such as by movement of the receiver, the adaptive optical element focal length changes to ensure that the cavity remains within its stability zone.

Optical waveguides interconnect optical information processing devices, or connect such devices with other optical communication links such as glass optical fibers. Fluoropolymers consisting of alternating perfluorocyclobutane and aryl ether linkages possess suitable properties for optical waveguides and other devices due to tunability in optical properties of the copolymers. Perfluorocyclobutane (PFCB) copolymer may be employed in solutions that exhibit a high solids content. Such solutions show useful physical properties for optical waveguide devices since the solutions are capable of achieving single step film thicknesses, when applied to a substrate, of greater than about 0.6 microns, and sometimes may achieve a thickness of 10 microns or more.

A method of film fabrication is taught that uses a coating and drying apparatus to fabricate resin films suitable for optical applications. In particular, resin films are prepared by simultaneous application of multiple liquid layers to a moving carrier substrate having low surface energy. After solvent removal, the resin films are peeled from the sacrificial carrier substrate. Films prepared by the current invention exhibit good dimensional stability and low out-of-plane retardation.

A color management system for use with projection displays includes, for example, two or more analyzers positioned to receive light beams as they are emitted from the panels of a color management system. The analyzers are positioned to receive the light beams directly from the image assimilators before the light has passed through another optical element such as a light combiner. The analyzers are configured for producing filtered light outputs with improved contrast relative to the incoming light beams. By positioning the analyzers to receive the light beams directly from the image assimilators, i.e., prior to passage through other optical elements, the analyzers are able to remove substantially all of the noise before it has become indistinguishable, on the basis of polarization, from the light that comprises the desirable image. Accordingly, this embodiment produces images having dramatically improved levels of contrast relative to prior art systems.

A reflective film includes a first optical stack that provides a first reflective characteristic and a second optical stack that provides a second reflective characteristic. The optical stacks also have first and second absorptive characteristics that are suitable to absorptively heat the respective stacks upon exposure to light including a write wavelength while maintaining the structural integrity of the stacks. The absorptive heating can change the first and second reflective characteristics to third and fourth reflective characteristics, respectively. A blocking layer that at least partially blocks light of the write wavelength may also be provided between the optical stacks to permit absorptive heating of any selected one of the optical stacks. The reflective characteristics of the optical stacks can thus be independently modified in any desired patterns by appropriate delivery of light beams that include the write wavelength.

A subject for the invention relates to processes for producing a polycarbonate containing a plant-derived starting material and to molded articles thereof, the polycarbonate having excellent mechanical strength, heat resistance, a low refractive index, a large Abbe number, low birefringence, and excellent transparency. The invention relates to a process for producing a polycarbonate which includes a step in which one or more dihydroxy compounds including a dihydroxy compound having at least one linking group —CH₂—O— in the molecule thereof are reacted with a carbonic acid diester in the presence of a polymerization catalyst, wherein the dihydroxy compound having at least one linking group —CH₂—O— in the molecule thereof has a formic acid content lower than 20 ppm. The invention further relates to a molded article constituted of a polycarbonate or a composition of the polycarbonate, the polycarbonate being a polycarbonate which contains constituent units derived from a dihydroxy compound having at least one linking group —CH₂—O— in the molecule thereof and has an Abbe number of 50 or larger and a 5% weight loss temperature of 340° C. or higher.

This invention seeks to provide a resin composition that can simultaneously satisfy resistances such as heat resistance and environmental resistance and moldability at high levels and that has excellent optical properties such as high refractivity and low birefringence and molded article thereof.

The present invention is a resin composition containing a polyester resin formed from a dicarboxylic acid component and a diol component (a) and a polycarbonate resin formed from a carbonate-forming component and a diol component (b), the diol component (a) containing a specific fluorene-containing compound and the diol component (b) containing a specific fluorene-containing compound.

A method of making an optical waveguide structure for an active PLC device having a reduced dn/dt birefringence. The method includes the step of forming a waveguide core layer on a bottom cladding, the waveguide core layer having a higher refractive index than the bottom cladding. The waveguide core layer is then etched to define a waveguide core. A top cladding is subsequently formed over the waveguide core and the bottom cladding. The top cladding also has a lower refractive index than the waveguide core. The top cladding is then etched to define a first trench and a second trench parallel to the waveguide core. The first trench and the second trench are configured to relieve a stress on the waveguide core. This stress can be induced by a heater, as in a case where the active PLC is a thermo-optic PLC. The first trench and the second trench can extend from an upper surface of the top cladding to an upper surface of the bottom cladding. The first trench and the second trench can extend from the upper surface of the top cladding into a portion of the underlying substrate. The first trench and the second trench are configured to balance a tensile stress within the waveguide core. A cap can be formed over the waveguide core prior to forming the top cladding to further balance the tensile stress within the waveguide core. The bottom cladding can have a higher dopant concentration than the top cladding.

The invention relates to a protective cover sheet comprising a low birefringence protective polymer film and a layer that promotes adhesion to poly(vinyl alcohol), the protective cover sheet comprising at least one functional layer containing a UV-absorbing polymer.

A laminated glass may be obtained by integrally bonding glass sheets through an adhesive, the adhesive comprising a hydrogenated block copolymer obtained by introducing an alkoxysilyl group into a hydrogenated block copolymer that is obtained by hydrogenating unsaturated bonds of a block copolymer that comprises at least two polymer blocks and at least one polymer block, the polymer block comprising a repeating unit derived from an aromatic vinyl compound as a main component, the polymer block comprising a repeating unit derived from a linear conjugated diene compound as a main component, and a ratio (wA:wB) of a weight fraction wA of the polymer block in the block copolymer to a weight fraction wB of the polymer block in the block copolymer being 30:70 to 60:40. The laminated glass may employ a block copolymer hydrogenation product comprising an alkoxysilyl group and excellent light-fastness, heat resistance, moisture resistance and transparency.

Injection molding, parts onto a carrier web (34) located between mold halves (18,20). Flow of polymer melt into the mold is assisted by application of ultrasonic energy to the mold cavity. After the molding operation, mold halves are separated, and the carrier web is advanced, or indexed, to a next position for another molding sequence. Molding apparatus comprises a moving mold face (20), that can move toward and away from a first mold member (18) (which can be stationary) in which the mold cavity is located, a means (24,25,26,30,32) for moving and/or indexing carrier web between the first mold member and the moving mold face, means (16) to inject polymer melt into the mold cavity, and an ultrasonic system (42) providing ultrasonic energy to the mold cavity. The carrier web can transport molded parts to subsequent process steps, such as coating, drying, inspection, curing, assembly or packaging.

The invention relates to a cushion isolating material which is arranged between a color film base panel and an array base panel of a liquid crystal panel. The cushion isolating material comprises a first component and a second component, wherein the first component comprises a first top part; the second component comprises a second top part; and the structures of the first top part and the second top part are matched concavely and convexly. Accordingly, the invention provides a preparation method of the cushion isolating material, the liquid crystal panel comprising the cushion isolating material, and a liquid crystal display device. The cushion isolating material can be used for effectively decreasing the stress between glass as a substrate in the liquid crystal panel, so that the anisotropy of the glass is decreased effectively, and the birefringence phenomenon of the glass is reduced. Therefore, the influence of the effective phase delay quantity (delta n*d) of the liquid crystal due to the phase delay quantity caused by the glass is eliminated, and the light leak of the liquid crystal panel is lightened correspondingly, i.e., the uniformity of luminance of light rays penetrating the liquid crystal panel is ensured, and the poor luminance effects such as a dark state Mura are decreased effectively. Consequently, the good display effect of the liquid crystal display device is realized.

The present invention relates to a multicore optical fiber having a structure for effectively inhibiting polarization mode dispersion from increasing, and the multicore optical fiber comprises a plurality of multicore units and a cladding region integrally covering the plurality of multicore units while separating the multicore units from each other. Each of the plurality of multicore units includes a plurality of core regions arranged such as to construct a predetermined core arrangement structure on a cross section orthogonal to an axis. The core arrangement structure of each multicore unit on the cross section has such a rotational symmetry as to coincide with the unrotated core arrangement structure at least three times while rotating by 360° about a center of the multicore unit, thereby reducing the structural asymmetry of each multicore unit. This lowers the structural birefringence in each multicore unit, thereby inhibiting the polarization mode dispersion from increasing in the multicore optical fiber.

A diffusely reflective optical film includes a blended layer extending from a first to a second zone of the film. The blended layer includes first and second polymer materials separated into distinct first and second phases, respectively. The blended layer may have the same composition and thickness in the first and second zones, but different first and second diffusely reflective characteristics in the first and second zones, respectively. The difference between the first and second diffusely reflective characteristics may not be attributable to any difference in composition or thickness of the layer between the first and second zones. Instead, the difference between the first and second diffusely reflective characteristic may be attributable to a difference in birefringence of the first and/or second polymer materials between the first and second zones. The blend morphology of the blended layer may be substantially the same in the first and second zones.

The invention relates to a protective cover sheet comprising a low birefringence protective polymer film and a layer containing a water-soluble polymer and polymer particles that promotes adhesion to poly(vinyl alcohol). The cover sheet has excellent adhesion to poly(vinyl alcohol)-containing dichroic polarizing films and eliminates the need to alkali treat the cover sheet prior to lamination to the dichroic films, thereby simplifying the process to manufacture polarizing plates.

The present invention provides a method for storing holographic data comprising providing a holographic storage medium comprising an optically transparent substrate including a photochemically active dye having at least two nitrone groups; and irradiating the optically transparent substrate with a holographic interference pattern, wherein the pattern has a first wavelength and an intensity both sufficient to convert, within a volume element of the substrate, at least some of the photochemically active dye into a photo-product, and producing within the irradiated volume element concentration variations of the photo-product corresponding to the holographic interference pattern, thereby producing a first optically readable datum corresponding to the volume element.