42results about How to "Low propagation loss" patented technology

A gradient index lens for electromagnetic radiation includes a dielectric substrate, a plurality of conducting patches supported by the dielectric substrate, the conducting patches preferably being generally square shaped and having an edge length, the edge length of the conducting patches varying with position on the dielectric substrate so as to provide a gradient index for the electromagnetic radiation. Examples include gradient index lenses for millimeter wave radiation, and use with antenna systems.

Electro-optic modulator devices and related waveguide components comprising BaTiO₃ films.

Surfaces of diamond crystals are examined by coating the surfaces with thin metal films, launching laser beams to the diamond surfaces in a slanting angle, detecting defects and particles on the diamond surfaces by the scattering of beams and counting the defects and particles by a laser scanning surface defect detection apparatus. Diamond SAW devices should be made on the diamond films or bulks with the defect density less than 300 particles cm-2. Preferably, the diamond surfaces should have roughness less than Ra20 nm. Diamond SAW filters can be produced by depositing a piezoelectric film and making interdigital transducers on the low-defect density diamond crystals.

A photosensitive resin composition for forming an optical waveguide comprises, at least, a polymer comprising at least one repeating structural unit represented by the following general formula (1):

wherein R¹ represents a hydrogen atom or methyl group; and R² to R⁵ each independently represent a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms, and a photoacid generator. This composition can form an optical waveguide pattern with excellent shape precision and at a low cost, and an optical waveguide of a low propagation loss.

A compound containing a crosslinkable moiety, a curable prepolymer, a blend, and a polymer sheet obtained therefrom, and an optical waveguide for optical interconnection. The compound is represented by the formula below:

Ar—H

• • wherein Ar includes a crosslinkable moiety at one end, a moiety selected from the group consisting of —O—, —S—, —COO—, —CO—, —COS—, —SO₂—, and —NH—, and one or two repeating units selected from the group consisting of the following repeating units:

A disclosed optical deflection element includes a magnesia spinel film 22, a lower electrode 23, a lower cladding layer 24, a core layer 25, and an upper cladding layer 26, which are sequentially stacked formed on a silicon single crystal substrate 21. The magnesia spinel film 22, the lower electrode 23, a PLZT film acting as the lower cladding layer 24, and a PZT film acting as the core layer 25 are epitaxially grown on respective underlying layers thereof. Because of a voltage applied between the lower electrode 23 and the upper electrode 26, refractive index variable regions 25A, 24A, in which the refractive index varies, are formed due to the electro-optical effect. Light incident into the core layer 25 is deflected at the interface between the core layer 25 and the refractive index variable regions 25A, 24A to the inner side relative to the surface of the core layer 25.

A surface acoustic wave filter includes a θ-rotated Y-cut X-propagation lithium niobate substrate. The cut angle ranges from 20° to 40°. An interdigital transducer can be used for exciting a surface acoustic wave that is formed on the substrate.

Provided are: a resin composition for the formation of an optical waveguide, which shows low transmission loss and high heat stability and enables to form a waveguide pattern at high shape accuracy and at low cost; an optical waveguide; a method of forming an optical waveguide; and an optical element using the method. A photosensitive resin composition is used, which includes a polyamic acid represented by a general formula (I) or a polyamic acid ester (A), a compound (B) having an epoxy group, and a compound (C) which generates an acid by being exposed to light.

Problems: an object of the present invention is to provide an optical waveguide-forming paste composition that allows short-time curing and provides excellent developability.

Means for Solving: The present invention is directed to an optical waveguide-forming paste composition including (A) barium sulfate particles with a mean particle diameter of 1 nm or more to 50 nm or less, (B) a compound having a polymerizable group and a carboxyl group, or a phosphoric ester compound having a polymerizable group, and (C) an organic solvent.

The present invention provides a resin composition for an optical waveguide and a resin film for optical waveguides, the composition and the film being soluble in an aqueous alkaline solution, being patternable as required by alkali development, and exhibiting a lower optical propagation loss at a wavelength of from 830 to 850 nm, and an optical waveguide using the composition or the film. The resin composition for an optical waveguide according to the present invention includes (A) a polymer, (B) a polymerizable compound, and (C) a polymerization initiator. A refractive index A of the film after irradiation with UV light and heat-curing and a refractive index B of the film after irradiation with UV light, immersion in an alkali developer, and then heat-curing satisfy the relationship of A>B. As an optical waveguide produced by alkali development using the resin composition according to the present invention has, on at least part of the periphery of a core pattern that forms a core layer, a portion having a refractive index that is lower than the refractive index of the central portion of the core pattern, the optical waveguide is effective in preventing light travelling through the core layer from leaking out into the cladding layer, which can lower optical propagation loss.

An optical beam splitter includes an input waveguide, two or more branching arms, two or more fan-out arms, and two or more output waveguides. The input waveguide receives an input light beam. The two or more branching arms are coupled to the input waveguide at a separation point and split the input light beam at the separation point into two or more light beams. Each fan-out arm is coupled to one of the branching arms and fans-out one of the two or more light beams to a predetermined output pitch. Each output waveguide is coupled to one of the fan-out arms and transmits one of the two or more light beams out of the optical beam splitter.

An optical waveguide-forming composition: 100 parts by mass of a reactive silicone compound (a) composed of a polycondensate of a diarylsilicic acid compound A of Formula [1]

Ar¹ and Ar² are a phenyl, naphthyl or a biphenyl group optionally substituted, and an alkoxy silicon compound B of Formula [2]

Ar³—Si(OR¹)_aR²_3-a  [2]

Ar³ is a phenyl, naphthyl or biphenyl group having at least one group having a polymerizable double bond, R¹ is methyl or ethyl group, R² is methyl, ethyl, or vinylphenyl group, and a is 2 or 3, and 1 part by mass to 200 parts by mass of a di(meth)acrylate compound (b) of Formula [3].

R³ and R⁴ are a hydrogen atom or methyl group, R⁵ is a hydrogen atom, methyl group, or ethyl group, L¹ and L² are an alkylene group, and m and n are 0 or a positive integer, wherein m+n is 0 to 20.

An optical waveguide device 1 includes a thin layer 3 and a ridge portion 5 loaded on the thin layer 3. The thin layer 3 is made of an optical material selected from the group consisting of lithium niobate, lithium tantalate, lithium niobate-lithium tantalate, yttrium aluminum garnet, yttrium vanadate, gadolinium vanadate, potassium gadolinium tungstate; and potassium yttrium tungstate. The ridge portion 5 is made of tantalum pentoxide and has a trapezoid shape viewed in a cross section perpendicular to a direction of propagation of light. The ridge portion is not peeled off from the thin layer in a tape peeling test.

A method is provided for forming a waveguide region within a periodically domain reversed ferroelectric crystal wherein the waveguide region has a refractive index profile that is vertically and horizontally symmetric. The symmetric profile produces effective overlapping between quasi-phasematched waves, a corresponding high rate of energy transfer between the waves and a symmetric cross-section of the radiated wave. The symmetric refractive index profile is produced by a method that combines the use of a diluted proton exchange medium at a high temperature which produces a region of high index relatively deeply beneath the crystal surface, followed by a reversed proton exchange which restores the original crystal index of refraction immediately beneath the crystal surface.

Light, which has been produced by a semiconductor device and has wavelengths falling within the range of 630 nm to 680 nm, is propagated through a plastic fiber provided with a core containing a polymethyl methacrylate as a principal constituent. The temperature of the semiconductor device is adjusted by a temperature adjusting system comprising a heater for heating the semiconductor device, a temperature detector for detecting the temperature of the semiconductor device and feeding out a temperature detection signal, and a control circuit for controlling actuation of the heater in accordance with the temperature detection signal in order to set the temperature of the semiconductor device at a predetermined target value that is lower than the highest temperature assumed to occur under an environment, in which the semiconductor device is located.

The present invention provides a method for manufacturing an optical member and an optical waveguide having a low optical loss. The provided method is capable of highly accurately controlling the positional configuration of refractive index distribution in the surface layer, including its vicinity, and the center portion of the core pattern in a transparent member. The method for manufacturing the optical member by the present invention has a Process A, in which the transparent member is exposed to a solution and thereby the refractive index of the surface layer of the transparent member exposed to the solution is substantially lower than that of the center portion of the transparent member not exposed to the solution. The substantial lowering of the refractive index of the surface layer is achieved by making the refractive index regulating agent exert its function by being included in the surface layer of the transparent member. The optical waveguide by the present invention has such a feature that surface layers of two or more sides on the circumference of the core pattern forming the core part have a refractive index lower than that of the center portion of the core pattern. The surface layer includes a refractive index regulating agent for lowering the refractive index. Further, a lower clad layer or an upper clad layer, or both, are provided outside the surface layer of low refractive index, wherein the refractive index of these clad layers are lower than that of the surface layer.