44results about How to "Low wavelength dependence" patented technology

Disclosed are a wire grid polarizer, which exhibits high polarization, p-polarized light transmittance, and s-polarized light reflectance in the visible light region, and the optical characteristics of which have low angular dependence and wavelength dependence, and a manufacturing method for the same. A wire grid polarizer (10) comprises a light transmissive substrate (14), on the surface of which a multiplicity of convex strips (12), the width of which gradually narrows from the base to the apex, is formed parallel to one another with intervening flat spots (13) formed between the convex strips (12), and at a specified pitch (Pp), and a metallic layer (20), which covers the entire surface of a first side face (16) of the convex strip (12) and a portion of the flat spot (13) adjacent thereto, and either does not cover a second side face (18) of the convex strip (12) or covers a portion of a second side face (18); and a manufacturing method forms a metallic layer (20) by vapor depositioning a metal or metal compound from a direction that is substantially orthogonal to the length direction of the convex strips (12) and forms a 25-40 DEG angle relative to the height direction of the convex strips (12) on the side of the first side face (16), under conditions in which the deposition amount is 40-60 nm.

An object of the present invention is to provide an optical waveguide device and an optical waveguide module having the function to multiplex / demultiplex or couple / decouple optical signals and particularly to provide an optical waveguide device and an optical waveguide module for realizing low optical loss, reducing wavelength dependence and ensuring easier shape management in the manufacturing and inspection processes. The optical waveguide device and optical waveguide module are provided with a substrate, one or more first waveguides, a plurality of second waveguides, and a slab waveguide for connecting the first waveguides and the second waveguides. At a region where the second waveguides are connected to the slab waveguide, a plurality of waveguide paths are provided for respectively connecting the second waveguides. Width of the waveguide paths is constant. The width of the separation gap between waveguide paths progressively increases as it becomes further away from the slab waveguide.

A broadband optical fiber tap for transferring optical energy out of an optical fiber having an optical fiber with a primary and secondary microbends for the purpose of coupling optical energy into the higher-order modes of the fiber, and a reflecting surface formed in the cladding of the fiber and positioned at an angle so as to reflect, by total internal reflection, higher-order mode energy away from the optical fiber. In the preferred embodiment, the two microbends are spaced apart by a distance approximately equal to one-half of the intermodal beat length for LP01 and LP11 modes of a single-mode fiber.

An electrochromic element includes a pair of transparent electrodes, and an electrolyte layer and an electrochromic layer disposed between the pair of transparent electrodes. Transmittance of light is changed by a voltage applied to the pair of transparent electrodes. The electrochromic layer includes a first electrochromic layer and a second electrochromic layer stacked upon each other. Both of the first and second electrochromic layers are made of titanium oxide. The first electrochromic layer is in contact with one of the pair of transparent electrodes. The second electrochromic layer is in contact with an electrolyte-layer side of the first electrochromic layer. A refractive index n0 of the transparent electrode in contact with the first electrochromic layer, a refractive index n1 of the first electrochromic layer, and a refractive index n2 of the second electrochromic layer satisfy the relationship n0<n1<n2.

A diffraction grating having a transparent supporting substrate; and a cured resin layer which is stacked on the transparent supporting substrate and which has concavities and convexities formed on a surface thereof, wherein when a Fourier-transformed image is obtained by performing two-dimensional fast Fourier transform processing on a concavity and convexity analysis image obtained by analyzing a shape of the concavities and convexities formed on the surface of the cured resin layer by use of an atomic force microscope, the Fourier-transformed image shows a circular or annular pattern substantially centered at an origin at which an absolute value of wavenumber is 0 μm−1, and the circular or annular pattern is present within a region where an absolute value of wavenumber is within a range of 10 μm−1 or less.

A polarizer in which parallel transmittance TP is increased and crossed transmittance TC is provided. Instead of arranging a plurality of all metal wires on one plane, a plurality of metal wires is separately formed on at least two different parallel planes, and adjacent meal wires among the plurality of metal wires are staggered in the polarizer. The heights of a first group of metal wires formed on a first plane and a second group of metal wires formed on a second plane, from a surface of the light-transmitting substrate are different. Further, a metal wire of the second group is provided to be more distant from the light-transmitting substrate than the first group of metal wires by distance D, and the distance D is smaller than the thickness of the first group of metal wires.

A light-reflective anisotropic conductive adhesive used for anisotropic conductive connection of a light-emitting element to a wiring substrate includes a thermosetting resin composition, conductive particles, and light-reflective insulating particles. The light-reflective insulating particles are formed by subjecting titanium oxide particles to a surface treatment with one kind selected from the group consisting of Al2O3, SiO, SiO2, ZnO, ZnO2, and ZrO2. The amount of the titanium oxide contained in the light-reflective insulating particles is 85 to 93%. The particle diameter of the light-reflective insulating particles is 0.2 to 0.3 μm, and the particle diameter of the conductive particles is 2 to 10 μm.

A Raman amplifier according to the present invention comprises a plurality of pumping means using semiconductor lasers of Fabry-Perot, DFB, or DBR type or MOPAs, and pumping lights outputted from the pumping means have different central wavelengths, and interval between the adjacent central wavelength is greater than 6 nm and smaller than 35 nm. An optical repeater according to the present invention comprises the above-mentioned Raman amplifier and adapted to compensate loss in an optical fiber transmission line by the Raman amplifier. In a Raman amplification method according to the present invention, the shorter the central wavelength of the pumping light the higher light power of said pumping light. In the Raman amplifier according to the present invention, when a certain pumping wavelength is defined as a first channel, and second to n-th channels are defined to be arranged with an interval of about 1 THz toward a longer wavelength side, the pumping lights having wavelengths corresponding to the first to n-th channels are multiplexed, and an pumping light having a wavelength spaced apart from the n-th channel by 2 THz or more toward the longer wavelength side is combined with the multiplexed light, thereby forming the pumping light source. The pumping lights having wavelengths corresponding to the channels other than (n-1)-th and (n-2)-th channels may be multiplexed, thereby forming the pumping light source. The pumping lights having wavelengths corresponding to the channels other than (n-2)-th and (n-3)-th channels may be multiplexed, thereby forming the pumping light source.

Provided are a wire-grid polarizer, which has not only a high degree of polarization, a high p-polarized light transmittance and a high s-polarized light reflectance but also a low angle dependency and a low wavelength dependency in terms of optical properties in a visible light region, and a process for producing the same.A wire-grid polarizer 10 comprising a light-transmitting substrate 14 having a plurality of ridges 12 formed in parallel to one another at certain pitches Pp through respective flat portions 13 disposed between adjacent ridges 12, each of the ridges having a width gradually reduced from a base portion to a top portion thereof, and a metal layer 20 composed of metal or a metal compound, the metal layer covering the entirety of a first lateral face 16 of each ridge 12 and a part of the flat portion 13 adjacent to the first lateral face 16 such that a second lateral face 18 of each ridge 12 is covered with no metal layer or is partially covered with the metal layer; and a process for forming the metal layer 20 by vapor-depositing metal or a metal compound on the first lateral face from a direction that is substantially orthogonal to a longitudinal direction of the ridges 12 and forms an angle of from 25 to 40 degrees toward the first lateral face 16 with respect to a height direction of the ridge 12 under conditions where the metal layer is disposed at a deposition amount of from 40 to 60 nm.

A light-reflective anisotropic conductive adhesive used for anisotropic conductive connection of a light-emitting element to a wiring board includes a thermosetting resin composition containing a silicone resin and a curing agent, conductive particles and light-reflective insulating particles. The light-reflective insulating particle is at least one kind of inorganic particles selected from the group consisting of titanium oxide, boron nitride, zinc oxide, silicon oxide, and aluminum oxide. The silicone resin is a glycidyloxyalkyl-alicyclic alkyl-modified organopolysiloxane.

It is an object of the present invention to provide a control technique for reducing wavelength dependence of wavelength dispersion values and also for suppressing a change in wavelength transmission characteristic with a temperature variation or the like, in a VIPA-type wavelength dispersion compensator. In order to achieve the object, the present VIPA-type wavelength dispersion compensator comprises: a VIPA plate capable of emitting incident lights in different directions according to wavelengths; a free-form surface mirror reflecting, at a previously set position, the lights of respective wavelengths emitted from the VIPA plate to return the reflected lights to the VIPA plate; a case provided with a heater which variably changes the temperature of the VIPA plate, a temperature sensor measuring the temperature of the VIPA plate and the ambient temperature; and a control section that reads out data which is measured or the like before starting the operation to be stored in a storing section, according to the measurement result of the temperature sensor, and optimizes the position of the free-form surface mirror and the temperature of the VIPA plate based on the read data.

A waveguide-type broadband optical isolator according to the present invention, comprising: a reciprocal phase shifter which makes a phase difference 3π / 2 between a first light wave propagating through a first waveguide and a second light wave propagating through a second waveguide, with a fundamental operating wavelength λ, and a nonreciprocal phase shifter which provides a phase difference π / 2 for forward propagating waves and a phase difference −π / 2 for backward propagating waves.

To provide optical elements such as a phase plate suitably used in a broadband range and a polarizing diffraction element excellent in diffraction efficiency, a polymerizable liquid crystal composition to be used for them, and an optical head device using them.A polymerizable liquid crystal composition containing a polymerizable compound having a mesogen structure comprising the following condensed benzene ring group (A) and the following 6-membered cyclic group (B) bonded to at least one bond in the group (A) directly or via a connecting group —OCO— or —COO—, and a monovalent terminal group bonded to each of both terminals of the mesogen structure, at least one of the terminal groups being a monovalent organic group having a polymerizable moiety:condensed benzene ring group (A): a naphthalenediyl group having bonds at 1-position and at 4- or 5-position, or an anthracenediyl group having bonds at 1- or 9-position and at 4-, 5- or 10-position;6-membered cyclic group (B): a 1,4-phenylene group, a trans-1,4-cyclohexylene group or a bivalent group having at least two groups selected from these groups bonded directly or via a connecting group.

A diffractive optical element includes a first optical part and a second optical part bonded to each other with a bonded surface therebetween configured as a diffraction surface. In this diffractive optical element, the diffraction order of diffracted light with the largest quantity of light out of diffracted light for one of a plurality of kinds of laser beams obtained on the diffraction surface is different from the diffraction order for at least another laser beam.

A variable optical attenuator includes a collimating unit that collimates an incident light beam, a polarization splitting member that separates the collimated light beam into a first polarized light beam having a first polarization and a second polarized light beam having a second polarization, a birefringence control unit through which the first and second polarized light beams pass, the birefringence control unit including a liquid crystal cell having a birefringence is controlled by a voltage or current, wherein the birefringence of the liquid crystal cell is substantially zero when no voltage or current is applied thereto, and a reflection member that reflects the first and second polarized light beams output from the birefringence control unit. The variable optical attenuator has high stability, high precision, and low volume.

Optical devices including a Faraday rotation devices improved in wavelength and temperature characteristics and an optical attenuator reduced in wavelength dependence and temperature-dependent loss. The Faraday rotation device has permanent magnets magnetized in an axial direction of through-holes, and Faraday elements having a same Faraday rotation direction with respect to a same magnetization direction. The permanent magnets are directed in the same magnetization direction along an optical path, where part of the Faraday elements are accommodated in the through-hole of the permanent magnet, and the remaining Faraday elements are arranged between the magnets, whereby the Faraday elements are to be applied by magnetic fields in opposite directions. For a device variable in Faraday rotation angle, an electromagnet is provided. An input fiber collimator and polarizer are provided on an input side of with the Faraday elements while an analyzer and output fiber collimator are on an output side.