59results about How to "Increased birefringence" patented technology

A method of producing a hologram element is disclosed that is able to prevent spread of a polymerization reaction and light leakage during exposure with interference light, and improve productivity in mass production. The hologram element is for transmitting, reflecting, diffracting, or scattering incident light, and includes a pair of substrates, an isolation member between the substrates that forms an isolated region, and a photo-sensitive recording material sealed in the isolated region. The hologram element includes a periodic structure formed by exposing the recording material to interference light. The interference light is generated by two or more light beams, or by using a master hologram. The recording material is formed from a composite material including a polymerized polymer or a polymerized liquid crystal. The periodic structure is formed by exposing the recording material to the interference light to induce the polymerization reaction and phase separation in the composite material.

A light-scattering film 10 is obtained by subjecting a birefringent material in a resin layer to orientation treatment, in which at least one component selected from a transparent resin 6 and a scattering material 7 is the birefringent material (e.g., a birefringent resin, a liquid crystalline material). According to the light-scattering film, in the case where a linear polarized light in which a vibrating direction and a propagating direction exist in a plane containing a surface-directional axis of the film and a thickness-directional axis of the film is incident at a film surface, the rectilinear transmittance of the incident light shows maximum at an oblique incident direction to the film surface (e.g., incident angle of 20 to 89°). The rectilinear transmittance of the incident light from a direction perpendicular to the film surface is 0 to 30%, and the rectilinear transmittance of the incident light from an oblique direction having an incident angle of 40 to 70° to the film surface is 50 to 100%. Directivity in a light-scattering property of the light-scattering film is improved, and even when an incident light comes from an oblique direction, brightness of the display surface from a front direction is improved. Therefore, the film is useful for employing in combination with a polarized plate of the liquid crystal display apparatus.

A cellulose acylate film that has: an in-plane retardation Re and a retardation Rth in a thickness direction at a wavelength of 590 nm, which are satisfied with ranges of expressions (I) to (III); a coefficient of a thermal expansion of from 20 ppm / ° C. to 100 ppm / ° C.; and a haze of from 0.01 to 0.8, and a polarizing plate and a display device using the same. 20≦Re≦50  Expression (I) 70≦Rth≦200  Expression (II) 1.0≦Rth / Re≦3.0  Expression (III) In the foregoing expressions, each of Re and Rth is a value at 25° C. and 60% RH, and has a unit of nm.

The nature of a volume hologram limits its use in security and sensing applications. Accordingly, a volume hologram segregated into a first and second region recording a first and second image, respectively, and wherein the second region is responsive to stimulus while the first region is protected physically from stimulus is provided. Also provided is a volume hologram with a functional cover disposed thereon to regulate how the volume hologram interacts with the stimulus when in the presence of stimulus. A volume hologram with a removable cover disposed thereon to permit a first recorded image to be viewed, to protect the volume hologram from physical damage, to prevent the volume hologram from interacting with the stimulus, and to be removed, thereby permitting the volume hologram to interact with the stimulus is provided as well. In these ways, the usability of volume holograms in security and sensing applications is increased.

A method for controlling positive birefringence in an optical compensation film (positive C-plate) having high positive birefringence throughout the wavelength range 400 nm<λ<800 nm is provided. The method includes selecting polymers with optically anisotropic subunits (OASUs) that exhibit the buttressing effect, wherein the OASUs may be disks, mesogens or aromatic rings substituted with birefringence enhancing substituents. The method further includes processing the polymer by solution casting to yield a polymer film with high birefringence without the need for stretching, photopolymerization, or other processes. These optical compensation films may be used in LCDs, particularly IPS-LCDs.

Optical compensation films (positive C-plate) with anisotropic subunits (OASUs) that are aromatic rings substituted with birefringence enhancing substituents (BES) and have high positive birefringence throughout the wavelength range 400 nm<λ<800 nm are provided. The optical compensation films may be processed by solution casting to yield a polymer film with high birefringence without the need for stretching, photopolymerization, or other processes. Such optical compensation films are suitable for use as a positive C-plate in LCDs, particularly IPS-LCDs.

A multilayer optical retardation compensation film having at least one positive C-plate and at least one negative C-plate is used in an LCD device. The multilayer film may have a substantially flat wavelength dispersion curve, or the multilayer film combined with other layers in the LCD device may have a substantially flat wavelength dispersion curve. Polymer films for the positive C-plate may be identified according to their absorbance maxima at certain wavelength ranges.

An optical film comprising a thermoplastic resin, which is such that the slow axis direction in the film plane differs from the film tilt direction and the birefringence of a sliced section of the film that contains the tilt direction and the thickness direction in the plane varies in the thickness direction of the film.

A cellulose acylate film that has: an in-plane retardation Re and a retardation Rth in a thickness direction at a wavelength of 590 nm, which are satisfied with ranges of expressions (I) to (III); a coefficient of a thermal expansion of from 20 ppm / ° C. to 100 ppm / ° C.; and a haze of from 0.01 to 0.8, and a polarizing plate and a display device using the same.20≦Re≦50  Expression (I)70≦Rth≦200  Expression (II)1.0≦Rth / Re≦3.0  Expression (III)In the foregoing expressions, each of Re and Rth is a value at 25° C. and 60% RH, and has a unit of nm.

Optical compensation films (positive C-plate) with anisotropic subunits (OASUs) that are aromatic rings substituted with birefringence enhancing substituents (BES) and have high positive birefringence throughout the wavelength range 400 nm<λ<800 nm are provided. The optical compensation films may be processed by solution casting to yield a polymer film with high birefringence without the need for stretching, photopolymerization, or other processes. Such optical compensation films are suitable for use as a positive C-plate in LCDs, particularly IPS-LCDs.

The invention discloses a TE die polarization analyzer based on a symmetrical three-waveguide directional coupler structure; the polarization analyzer comprises a silicon-based substrate (9), a buried oxide (10), a polarization analyzing part (15) and an upper cladding (11) arranged from bottom to top; the buried oxide (10) grows on the top surface of the silicon-based substrate (9); the upper cladding (11) covers the top surface of the buried oxide (10); the polarization analyzing part (15) horizontally grows on the top surface of the buried oxide (10), and is covered by the upper cladding (11); the polarization analyzing part (15) comprises an input channel (1), a middle path direct through channel (2), a left path direct through channel (4), a left path C-type bending channel (5), a right path direct through channel (6), a right path C-type bending channel (7) and an output channel (3); the TE die polarization analyzer is low in insertion loss, high in extinction ratio, large in work bandwidth, and compact in structure.

Optical compensation films (positive C-plate) with disk anisotropic subunits (OASUs) that have high positive birefringence throughout the wavelength range 400 nm<λ<800 nm are provided. The optical compensation films may be processed by solution casting to yield a polymer film with high birefringence without the need for stretching, photopolymerization, or other processes. Such optical compensation films are suitable for use as a positive C-plate in LCDs, particularly IPS-LCDs.

The present invention provides a photorefractive hybrid cell including a window and a gain media disposed adjacent the window. The gain media includes nanoparticles therein. The window includes a material that forms a space-charge field. The gain media includes a material having refractive index properties that depend on an electric field. The nanoparticles include a material which responds orientationally to the presence of an electric or magnetic field.

An optical film comprising a thermoplastic resin and having a tilt direction, which is such that, when a sliced section of the optical film having both a tilt direction and the thickness direction of the film in the sliced plane thereof is placed between two polarizers set in a crossed Nicols configuration, and the two crossed Nicols polarizers are rotated from 0° to 90° while irradiated with light in the direction perpendicular to the polarizer plane, and when the sliced section is analyzed sequentially from one end to the other end in the thickness direction, then all the detected extinction positions are from more than 0° to less than 90° and the birefringence varies in the thickness direction.

The present invention relates to a high-speed high-temperature nematic liquid crystal composition and a liquid crystal display comprising the same, particularly to a high-speed high-temperature nematic liquid crystal composition which comprises a nematic liquid crystal compound having an isothionate group on the end aromatic ring and having one or more kinds of fluorine atoms, and thus satisfies a high response speed property and has a high phase transition temperature of liquid crystal, a low operating voltage, and a broad nematic phase temperature range, and a liquid crystal cell comprising the same, and a liquid crystal display using the same.

The present invention relates to an eigenmode completely separate type degenerated multimode fiber. The degenerated multimode fiber comprises a birefringence fiber core, a stress region and a cladding. The birefringence fiber core provides the shape structure birefringence, and adopts an elliptical-core / elliptical ring-shaped fiber core structure. The stress region provides a stress additional birefringence and adopts a circular (panda type) or fan ring-shaped (bow-tie / butterfly-shaped) structure. The shape structure birefringence and the stress additional birefringence are superposed, so that the multi-channel eigenmode is enabled. Meanwhile, the difference among the effective refractive indexes of all eigenmodes is larger than 1*10-4 simultaneously. As a result, all eigenmodes are completely separated and degenerated. According to the technical scheme of the invention, the number of optical fiber degenerated eigenmodes is increased, and the crosstalk among the eigenmodes is reduced. The degenerated multimode fiber can be applied to the optical fiber multi-channel eigenmode multiplexing communication, while the multiple-input and multiple-output digital signal processing technique is not required. Based on the manufacturing process of panda type / bow-tie type / butterfly type elliptic-core polarization-preserving fibers and ring-shaped optical fibers, the eigenmode completely separate type degenerated multimode fiber is convenient for actual drawing.

The present invention relates to a nematic liquid crystal compound and a liquid crystal composition exhibiting a fast response time over a wide temperature range comprising the same, and more particularly, to a liquid crystal composition with fast response characteristics, and having a high phase transition temperature of liquid crystal, and having a low driving voltage and a nematic phase in a wide temperature range, comprising a nematic liquid crystal compound having an isothionate group and at least one fluorine atom in an aromatic ring of a terminal group.

The present invention provides materials and methods that make liquid crystal phases accessible with relatively short β-peptides in aqueous solvents.

A nematic liquid crystal composition includes a compound of formula (1) and a host mixture:wherein ‘R’ is chosen from CnH2n+1O, CnH2n+1, CnH2n+1S or CnH2n−1; ‘n’ is an integer of 1 to 15; ‘A’ is‘a’ is 0 or 1; ‘B’ is —CH2CH2—, —C═C—, —C≡C— or‘b’ is 0 or 1; ‘D’ is—CH2CH2—, —C═C— or —C≡C—; ‘d’ is 0 or 1; ‘X’ is H, F, Cl, Br, NCS or CN; and ‘Y’ is from NCS, SCN or F. A liquid crystal display apparatus employing the nematic liquid crystal composition has a high response speed and a high phase transition temperature. In addition, the nematic liquid crystal composition has an augmented birefringence and a dielectric anisotropy. The liquid crystal display apparatus using the nematic liquid crystal composition may have an enhanced brightness.

The present invention provides a photorefractive hybrid cell including a window and a gain media disposed adjacent the window. The gain media includes nanoparticles therein. The window includes a material that forms a space-charge field. The gain media includes a material having refractive index properties that depend on an electric field. The nanoparticles include a material which responds orientationally to the presence of an electric or a magnetic field.

A nematic liquid crystal composition includes a compound of formula (1) and a host mixture: wherein ‘R’ is chosen from CnH2n+1O, CnH2n+1, CnH2n+1S or CnH2n−1; ‘n’ is an integer of 1 to 15; ‘A’ is ‘a’ is 0 or 1; ‘B’ is —CH2CH2—, —C═C—, —C≡C— or ‘b’ is 0 or 1; ‘D’ is —CH2CH2—, —C═C— or —C≡C—; ‘d’ is 0 or 1;‘X’ is H, F, Cl, Br, NCS or CN; and ‘Y’ is from NCS, SCN or F. A liquid crystal display apparatus employing the nematic liquid crystal composition has a high response speed and a high phase transition temperature. In addition, the nematic liquid crystal composition has an augmented birefringence and a dielectric anisotropy. The liquid crystal display apparatus using the nematic liquid crystal composition may have an enhanced brightness.

The invention is directed to a method for processing and annealing metal fluoride single crystals. Among other steps, the method includes of removing the as-grown surfaces of the crystals after they emerge from the growth furnace, processing the surfaces in such way that all the crystal surfaces have the same thermal properties, and then placing the crystals in a secondary annealing furnace to further anneal the crystals to release the residual stresses resulting from the primary annealing process. The invention is suitable for metal fluoride crystals of general formula MF2, where M is calcium, magnesium, barium and strontium, and mixtures thereof.

The invention relates to an octagonal photonic crystal optical-fiber polarization beam splitter. The octagonal photonic crystal optical-fiber polarization beam splitter comprises two fiber cores which are distributed in a central symmetry manner and a cladding layer, wherein the cladding layer is formed by circular air holes and a background material, the cladding layer is arranged in a peripheral area of the fiber cores, and the refractive index of the cladding layer is lower than that of the fiber core part; the circular air holes forming the cladding layer are distributed in an octagonal shape surrounding the fiber cores, an elliptical air hole is formed between the two fiber cores, and on the end surface of the photonic crystal optical-fiber polarization beam splitter, all the circular air holes are identical in bore diameters. The octagonal photonic crystal optical-fiber polarization beam splitter has the advantages that the distribution way of the air holes in the optical-fiber cladding layer is improved, so that the asymmetry of the structure is improved, and the optical fibers have high double refractive effect. Meanwhile, the photonic crystal optical-fiber polarization beam splitter has the advantages of high extinction ratio, large bandwidth and the like.

Disclosed in a novel liquid-crystalline compound which is a naphthalene derivative useful as an electro-optical liquid crystal display material, a liquid crystal composition containing such naphthalene derivatives and a liquid crystal display device comprising the same. The naphthalene derivative provided by the present invention exhibits an excellent liquid-crystallinity and miscibility with currently widely used liquid crystal compositions or compositions. The addition of the naphthalene derivative makes it possible to drastically lower the threshold voltage of the liquid crystal composition while maintaining its high response. The naphthalene derivative of the present invention is characterized by a large birefringence index. Further, most of the naphthalene derivative of the present invention has no strongly polar group in its molecule and thus can also be used for active matrix driving. Moreover, as shown in the foregoing examples, the naphthalene derivative of the present invention can be easily produced and is colorless and chemically stable. Accordingly, the liquid crystal composition comprising the naphthalene derivative of the present invention is extremely useful as a practical liquid crystal composition, particularly a liquid crystal composition which can operate within a wide temperature range and requires a high speed response and a low voltage driving.

The invention discloses a quasi-D-type photonic crystal fiber sensor based on surface plasmas, and belongs to the field of fiber sensors. According to the sensor, elliptical air holes are introduced into the two sides of the fiber core, so that the birefringence effect is enhanced, and the performance of the sensor is improved; the ITO film is used, so that the working wavelength of the sensor isexpanded to a near-infrared light band; by introducing the graphene layer, the adsorption capacity of the sensor for biological analysis is improved, so that the sensor can be applied to the field ofbiological sensing. The sensor provided by the invention is superior to the existing sensor in detectable refractive index range, sensitivity and resolution, and due to the adoption of the quasi-D-shaped structure, the toughness of the sensor is much higher than that of the traditional D-shaped sensor, and the sensor has the potential of commercial application.

Described herein are novel azo-benzene type chromophores. The chromophores are useful in photochromic compositions comprising a polymer matrix and a chromophore, wherein the chromophore is a novel azo-benzene type structure. The photochromic composition is photoresponsive upon irradiation by at least one wavelength of laser light across the visible light spectrum. Photochromic devices which comprise the novel azo-benzene type chromophore compound show significantly higher photoinduced birefringence, higher diffraction efficiency, and brighter images than devices that comprise well known azo-benzene chromophores. The photochromic composition may include a liquid crystal.

A multilayer optical retardation compensation film having at least one positive C-plate and at least one negative C-plate is used in an LCD device. The multilayer film may have a substantially flat wavelength dispersion curve, or the multilayer film combined with other layers in the LCD device may have a substantially flat wavelength dispersion curve. Polymer films for the positive C-plate may be identified according to their absorbance maxima at certain wavelength ranges.