Hitachi Cable, Inc.

Fuji Jukogyo Kabushiki Kaisha

Japan Aviation Electronics Industry, Limited

Toyota Jidosha Kabushiki Kaisha

Hitachi Metals, Ltd.

The University of Tokyo

Ntt Communications Corporation

Toyota School Foundation

Advanced Cable Systems Corp.

Seiji Kojima

Kanako Suzuki

Yoshikazu Namekawa

Akihito Hongo

Kazumasa Ohsono

Bing Yao

Yuichi Koreeda

Naoki Katagiyama

Toshimichi Ogisu

Yoshinori Kurosawa

Mikio Ohkoshi

Hiroshi Ito

Daisuke Inoue

Akio Sato

Tadashi Ichikawa

Nobuo Takeda

Kojiro Ito

Kazuo Hasegawa

Yoshihiro Nakatani

Kazuya Saito

Takao Nishikawa

Kohei Yanaka

Toshihiko Ishikawa

Tetsuya Sueoka

Shinji Komatsuzaki

In an optical connector, end faces of a pair of ferrules that hold multiple optical fibers are positioned with two guide pins and butted against each other to connect the optical fibers in the pair of ferrules. The optical connector is provided with an urging member for pushing the end faces against each other. The end faces are ground at an angle. The gap between the guide pins and guide holes, which open at the end faces and into which the guide pins are fitted, is larger than 0.004 mm and smaller than or equal to 0.008 mm. Powder caused by the friction generated when the guide pins are inserted and fitted into the guide holes is greatly reduced. Connection loss does not increase even when frequent connection and disconnection are performed, and cleaning the connector becomes unnecessary.

Optical connector

An optical fiber connecting part has a ferrule, and a guide bore penetrating through the ferrule and configured to guide an optical fiber to be inserted. The guide bore has a first bore provided at one end of the ferrule, through which the optical fiber is inserted into the ferrule, a second bore provided at another end of the ferrule, the second bore having an inner diameter smaller than an inner diameter of the first bore, and an intermediate bore provided between the first bore and the second bore to directly connect between the first bore and the second bore. A center axis of the second bore is shifted from a center axis of the first bore.

Optical fiber connecting part and optical module using the same

An optical fiber has a single-layer coated optical fiber having an optical bare fiber including a core and a clad formed around the core, and a single coating layer provided around an outer periphery of the optical bare fiber, an inner coating layer provided around an outer periphery of the single-layer coated optical fiber, which contacts with the single coating layer, and an outer coating layer formed as a collective coating layer around an outer side of the inner coating layer. The inner coating layer has a Young modulus lower than a Young modulus of the single coating layer and a Young modulus of the outer coating layer.

Optical fiber, tape-like optical fiber and optical module using the same

Guide pin for optical connector

A composite cable that is able to prevent both the unfastening of the cable end from the connector and the occurrence of the bending distortion of the optical fiber, to both of which the expansion and shrinkage of the overall sheath is responsible, is provided. The composite cable comprises a stranded wire that is a strand of a plurality of insulated conductors each of which is a conductor with insulation covering thereon, an optical fiber ribbon that has a plurality of optical fibers parallelly-arranged in a row, and an overall sheath that covers the stranded wire and the optical fiber ribbon in a bundle, wherein the composite cable has a deterrent positioned on outer side of the stranded wire and the optical fiber ribbon parallelly-arranged in a row along the width direction of the overall sheath for deterring expansion and shrinkage of the overall sheath. Further, the composite cable has a bonding jacket between the deterrent and the overall sheath for making the deterrent adhere to the overall sheath; alternatively, the deterrent has a patterned indented shape on the surface thereof for making the deterrent adhere to the overall sheath.

Composite cable

An optical connector that permits an optical fiber ribbon to be led out in multiple directions and an optical fiber module that uses the optical connector are provided. The optical connector comprises a connector main body and a guide groove formed on the connector main body in which an optical fiber ribbon is arranged, wherein the guide groove is comprised of an end face holding slot, a vertical guiding face, an arcuate guiding face formed in arc-shape, and a positioning face for widthwise positioning and fixing the optical fiber ribbon and wherein the vertical guiding face and the arcuate guiding face and the positioning face define a space that opens toward a top face of the connector main body; and the optical fiber module comprises the optical fiber ribbon and the optical connector.

Optical connector and fiber module

A communication light detecting device interconnecting light transmission paths and collocated therebetween, comprises: an optical coupling body including a core portion for photo coupling with the light transmission paths, and a light extracting portion for extracting a part of the communication light as a leakage light; and a light detecting portion having a light receiving member for receiving the leakage light. The light extracting portion is preferable to possess a lower refractive index than that of the core portion. Besides, the light extracting portion is preferable to include a light detecting use groove with a groove width of 50 &#x3bc;m or more and 140 &#x3bc;m or less formed by cutting and separating the core portion. Besides, the light extracting portion is preferable to be the optical coupling body in which outer diameter of the core portion is different from the outer diameter of a core of the light transmission path.

Communication light detecting device

In an embodiment of the invention, an optical connector for optically coupling respective end faces of two optical fiber cables including an optical fiber composed of a core and a cladding includes a beat shrinkable tube, a cable insertion tube disposed in the heat shrinkable tube for inserting thereinto and butting the respective end faces of the two optical fiber cables, an uncured refractive index matching resin disposed between the beat shrinkable tube and the cable insertion tube, and a resin supply hole formed in the cable insertion tube for supplying the uncured refractive index matching resin to an inside of the cable insertion tube. In an alternative embodiment, an optical connector includes a protection sleeve, a cable insertion tube disposed in the protection sleeve for inserting thereinto and butting the respective end faces of the two optical fiber cables, an optical instantaneous adhesive material disposed between the protection sleeve and the cable insertion tube, and an adhesive material supply hole formed in the cable insertion tube for supplying the optical instantaneous adhesive material to an inside of the cable insertion tube.

An optical fiber laser, according to the present invention, has an optical fiber including a core to which a rare earth element is added and a clad disposed around the core, and also has an excitation light source for emitting excitation light incident on a side of the optical fiber. The optical fiber has a corrugated shape on the outer circumference of the clad along the longitudinal direction thereof; and the optical fiber is wound in a spiral form and is bundled in such a way that adjacent sides of the clad are brought into contact with one another.

Optical fiber laser and exciting method using same

The optical fiberfor an optical fiber laser is provided with a rare earth element doped coredoped with a rare earth element, and a claddingformed at an outer periphery of the rare earth element doped core. In the optical fiberfor an optical fiber laser, the rare earth element doped coreis divided into a plurality of core regions&#x2212;1,along a longitudinal direction of the optical fiberand dopant concentrations of the rare earth element in respective core regions&#x2212;1,are different from each other, in order to flatten a temperature distribution of the optical fiberalong the longitudinal direction.

Optical fiber for an optical fiber laser, method for fabricating the same, and optical fiber laser

A physical quantity measuring system according to the present invention comprises: an optical fiber having fiber Bragg gratings; a light source connected to the optical fiber; an arrayed waveguide grating connected between the light source and the optical fiber via an optical branching filter, and having output channels of which central wavelengths of at least three output channels are included in a one-tenth loss band of a reflected light by the fiber Bragg grating; light receiving devices for receiving light output from the output channels on a one-to-one basis; and a central reflected wavelength change detecting unit connected to the light receiving devices for estimating a change in a central reflected wavelength based on a physical quantity, by calculating first and second group signals from light receiving signals corresponding to the at least three output channels, and by calculating a differential signal between the first and the second group signals.

Physical quantity measuring apparatus

In an embodiment of the invention, an optical connector for optically coupling respective end faces of two optical fiber cables including an optical fiber composed of a core and a cladding and a covering layer covering the optical fiber includes a protection sleeve, a cable insertion tube disposed in the protection sleeve for inserting thereinto and butting the respective end faces of the two optical fiber cables, an uncured refractive index matching material disposed between the protection sleeve and the cable insertion tube, and a supply hole formed in the cable insertion tube for supplying the uncured refractive index matching material to an inside of the cable insertion tube. The cable insertion tube includes a cable receiving room for receiving an end of the two optical fiber cables inserted, a fiber receiving room for receiving the optical fiber, and a covering removal member formed at a boundary of the cable receiving room and the fiber receiving room for removing the covering layer.

A cladding is provided at an outer periphery of a solid-core doped with rare earth ions, and a metal layer is formed to be adjacent to the cladding to provide an optical fiber for a fiber laser device. The metal layer having an inner metal layer and an outer metal layer is disposed along an entire length of the optical fiber for a fiber laser device. An exciting light is incident to the optical fiber for a fiber laser device, and the exciting light is reflection-excited to emit a high power laser oscillation light. A monitoring current is constantly flown into the metal layer. When the disconnection of the optical fiber for a fiber laser device is detected based on the monitoring current, the energization of the optical fiber for a fiber laser device is stopped.

Optical fiber for fiber laser device and fiber laser device using same

A physical quantity measuring system includes an optical fiber in which plural fiber Bragg gratings having different reflection wavelength changing bands are formed along the optical fiber in a longitudinal direction, a light source which outputs a broadband light into the optical fiber, an arrayed waveguide grating and an operating portion. The arrayed waveguide grating divides a light reflected by the fiber Bragg grating and outputted from the optical fiber into plural divisional wavelength bands. The arrayed waveguide grating outputs the divided lights to output channels. The operating portion detects a change of a reflected center wavelength of each fiber Bragg grating by a change of an output of each light-receiving element, operates a physical quantity and a position thereof given to the optical fiber, and is capable of detecting light from adjacent output channels.

Physical quantity measuring system with fiber Bragg grating sensor and arrayed waveguide grating

A damage detection system including: a optical fiber sensor including a core portion to have a grating portion formed therein, the grating portion having gratings reflecting light, wherein a wavelength band of the reflected light changes when a distance between adjacent gratings changes; a light source to input broadband light into the core portion; two optical filters connected to an output end of the sensor; and an apparatus to perform arithmetic processing on output values of the optical filters, wherein each passband of the optical filters overlaps with the vibration range of the wavelength band, in which a center wavelength of one of the passbands is fixed to an upper area of a vibration center of a center wavelength of the reflected light and that of the other of the passbands is fixed to a lower area thereof.

Growing community of inventors

Hitachi, Japan

Seiji Kojima