Fujikura Limited

Hokkaido University

Yoshihiro Terada

Koji Omichi

Kuniharu Himeno

Mitsuru Kamikatano

Bunsho Ohtani

Tsukasa Torimoto

Takamune Yamagami

Kazuhiko Aikawa

Kentaro Ichii

Masakazu Ohashi

Kazuyuki Hayashi

Katsuaki Izoe

Daiichiro Tanaka

Manabu Kudoh

Rintaro Morohashi

Koji Azegami

Yutaka Endoh

A method for detecting a non-superconducting transition of a superconducting wire including a substrate, a superconducting layer having a critical temperature of 77 K or more, and a metal stabilization layer includes, adhesively attaching an optical fiber where a plurality of fiber Bragg gratings are formed in a core along a longitudinal direction thereof to the superconducting wire; measuring in advance a Bragg wavelength shift of the fiber Bragg gratings for a temperature variation of the superconducting wire, and determining a relational expression based on the shift for a temperature calculation of the superconducting wire; determining temperature variations of the fiber Bragg gratings before and after the non-superconducting transition of the superconducting wire using the relational expression; and calculating a propagation rate of the non-superconducting transition based on both a time difference of temperature increases of the fiber Bragg gratings, and an interval between each of the fiber Bragg gratings.

Method for detecting non-superconducting transition of superconducting wire

Optical pulses are output from a light source to an optical fiber at one selected emission wavelength, a reflection light reflected at a fiber Bragg grating at the optical fiber is received at an optical receiver and is converted to a reflection signal by an optical to electrical conversion, a fiber Bragg grating which reflects the reflection light is identified by the signal processing unit when an intensity of the reflection signal obtained by the optical receiver is over a predetermined threshold value, and a measurement step that calculates acoustic frequencies at the fiber Bragg grating based on a temporal change of the intensity of the reflection signal at the fiber Bragg grating is repeated more than two times while changing an emission wavelength of the light source. The acoustic frequency at each fiber Bragg grating is calculated to determine an acoustic distribution along a longitudinal direction of the fiber.

Method of measuring acoustic distribution and distributed acoustic sensor

The polarization-maintaining fiber of the invention includes a core () made of germanium doped silica glass; a stress-applying part () made of boron doped silica glass; a cladding () made of pure silica glass; and a polyimide coating layer () with a thickness of 10 &#x3bc;m or less that surrounds the outer periphery of the cladding ().

Polarization-maintaining fiber and optical fiber sensor using same

A method for manufacturing an optical fiber grating that includes first and second gratings that configure an optical resonator, the method including: forming the first grating by radiating ultraviolet light to an optical fiber so that a irradiation intensity Z satisfies the following Equation 1: Z&#x2266;(&#x394;&#x3bb;/x+0.04556Y+1.2225Y)/(0.05625Y+1.6125Y) . . . Equation 1, where, Z represents an irradiation intensity (mJ/mm) of the ultraviolet light, &#x394;&#x3bb;represents the maximum shift amount of a reflection center wavelength of the first grating that is allowed as long as reflection wavelengths of the first grating and second grating overlap each other, x represents a shift amount of the reflection center wavelength per temperature change of 1&#xb0; C. (nm/&#xb0; C.) in the first grating, and Y represents an intensity (W) of the wave-guided light.

Method for manufacturing optical fiber grating, optical fiber grating, and fiber laser

The invention relates to nanostructure and its manufacturing method. In the manufacturing method of a nanostructure, first anisotropic crystalline particles, connectors having end to be connected to a specific crystal face of each of said crystalline particles, and second particles to be connected to the other end of each of said connectors are prepared. First ends of the connectors are connected to specific crystal faces of the first crystalline particles, and simultaneously or before or after the connection, the second ends of the connectors are connected to the second particles. A nanostructure formed by this method has a three-dimensional structure which does not have a closest packing structure.

Nanostructure and manufacturing method for same

A manufacturing method of an optical communication module for manufacturing the optical communication module, including the sequentially performed steps of: (1) mounting a light-emitting element and a light-receiving element on a side surface of a sub-mount substrate and mounting the sub-mount substrate on a printed circuit board such that the light-emitting and -receiving directions of the light-emitting element and light-receiving element are parallel to the printed circuit board; (2) aligning an optical waveguide; and (3) dropping resin solution on an area of the sub-mount substrate including an optical waveguide end and the light-emitting element or the light-receiving element, and curing the resin solution. According to the present invention, it is possible to provide an optical communication module which can be made thin, small and cheap.

Optical communication module, manufacturing method therefor, and optical transceiver

The invention relates to nanostructure and its manufacturing method. In the manufacturing method of a nanostructure, first anisotropic crystalline particles, connectors having an end to be connected to a specific crystal face of each of said crystalline particles, and second particles to be connected to the other end of each of said connectors are prepared. First ends of the connectors are connected to specific crystal faces of the first crystalline particles, and simultaneously or before or after the connection, the second ends of the connectors are connected to the second particles. A nanostructure formed by this method has a three-dimensional structure which does not have a closest packing structure.

Growing community of inventors

Sakura, Japan

Yoshihiro Terada