Hitachi, Ltd.

The Furukawa Electric Co., Ltd.

Hitachi Maxell, Limited

Nippon Telegraph and Telephone Corporation

Pentax Corporation

Nippon Light Metal Company, Ltd.

Shinichi Arai

Takuya Mizokami

Takeshi Maeda

Koichi Sugimoto

Atsushi Saito

Ryuichi Sugizaki

Takeshi Yagi

Satoshi Kawamura

Keiichi Aiso

Naoto Oyama

Yoshihisa Kamo

Hisashi Koaizawa

Yasuhiro Katoh

Naoki Sato

Toyohide Hamada

Hisaaki Hirabayashi

Shiyuki Sakaue

Shigeto Matsumoto

Jun Terada

Kazuo Isaka

Kiyohide Koizumi

Katsunori Inoue

Hiroshi Kikuchi

Hisataka Sugiyama

Akira Arimoto

Kazuo Shigematsu

Hideaki Hasegawa

Masanori Takahashi

Masaru Eguchi

Kazuhide Nakajima

Hidehiko Takara

Youichi Akasaka

Koichi Maeda

Satoki Kawanishi

Noritsugu Enomoto

Masahiro Takasago

Minoru Kosuge

Kiyoharu Kishimoto

Masayoshi Tsukamoto

Shinichi Aozasa

Kazuhiro Momata

Hirofumi Saito

Kunihiko Mori

Kyozo Tsujikawa

Masahiko Katano

Kikuo Shimizu

Tamotsu Iida

Harumi Inaba

Tamotsu Kamiya

Hiroyuki Tamaoka

Hiroyuki Tsukamoto

Michio Takahashi

Hidetoshi Inaba

Masashi Isobe

Chihiro Mochizuki

Tatsuhiro Suzuki

Tooru Mita

Minsuk Song

Tomoyuki Masui

Histaka Sugiyama

A pressure sensor includes: a light source that outputs signal light; a sensor optical fiber where the signal light is input and the signal light is propagated with a loss of 0.3 dB/m or more; and an optical receiver that receives the signal light propagated through the sensor optical fiber. Further, pressure applied to the sensor optical fiber is detected on a basis of intensity of the signal light received by the optical receiver.

Pressure sensor

A multicore fiber includes: n pieces of first core regions in a circular shape with a radius rthat are arranged about points Pto P, and that has a first core portion and a first cladding portion; a second core region in a circular shape with a radius Rthat is arranged about the point a, and that has a second core portion and a second cladding portion; and a cladding region that is formed on an outer circumferences of the first core region and the second core region. Further, abutting surfaces that are flat surfaces abutting on each other are formed in portions on the outer circumferences of the first core region and the second core region.

Manufacturing method of multicore fiber preform, multicore fiber preform, and multicore fiber

A method for screening an optical fiber core including a resin coating layer, includes: a pre-strain applying step of adding a tensile force while feeding a portion of the optical fiber core retained at both ends of the portion, and applying a pre-tensile strain larger than zero and smaller than a guaranteed tensile strain set as a guaranteed value; a guaranteed strain applying step of adding a tensile force while feeding the portion of the optical fiber core retained at both ends of the portion and applied with the pre-tensile strain, and applying the guaranteed tensile strain only for a predetermined time; and a guaranteed strain releasing step of releasing the optical fiber core from the guaranteed tensile strain.

Method and device for screening optical fiber core, and method for manufacturing optical fiber core

An optical fiber manufacturing method includes setting a first holding member and a rod inside a glass pipe, the first holding member made of glass and having plural holes formed, so that the rod is supported by the first holding member; filling glass particles between the rod and a glass pipe inner wall; holding the rod such that the rod and the filled glass particles are enclosed by the glass pipe inner wall and the first and second holding members, and sealing one end of the glass pipe and manufacturing an intermediate; and manufacturing an optical fiber from the intermediate, wherein a bulk density of the first and second holding members is set with reference to a bulk density of a filling portion made from the glass particles, and the predetermined range is determined according to a core diameter permissible variation range in its longitudinal direction.

Optical fiber manufacturing method using relative bulk densities

An image acquisition apparatus includes an image pickup device that includes a plurality of pixels, and a filter layer that blocks propagation of an incident light ray which comes from an object side to the pixel side in accordance with an increase in incident angle of the incident light ray.

Image acquisition apparatus and biometric information acquisition apparatus

A coating is applied on an optical fiber drawn from a melted tip of an optical-fiber preform. A glass spin is applied to a coated optical fiber by gripping the coated optical fiber with at least a pair of spinning applying rollers arranged in different levels with parallel rotation axes, rotating the spinning applying rollers so that the coated optical fiber is guided in a predetermined direction, and alternately shifting the spinning applying rollers in opposite directions along the rotation axes. The glass spin is applied to the coated optical fiber in a state in which each of the rotation axes is tilted at a predetermined angle from a plane perpendicular to the first direction.

Method of manufacturing optical fiber

A solid-state image pickup device including a substrate having a first face and a second face which serves as an opposite face of the first face; a solid-state image pickup element having a plurality of electrodes and a light sensing part, an opposite face of the light sensing part being bonded to the first face via a bonding agent; a plurality of wires formed over the face, first ends of the wires serving as external electrode terminals; and a connection part for electrically connecting the electrodes to the wires, wherein an endless-shaped contraction frame formed of resin larger in thermal expansion coefficient than the substrate and image pickup element is bonded to and formed on surface of the substrate located outside the light sensing part so as to surround the light sensing part, and a light sensing face of the light sensing part is warped.

Solid-state image pickup device and method of producing the same

An aluminum plate having an aluminum purity of not less than 99.98% by mass and an Fe content of 5 to 50 ppm with the balance consisting of unavoidable impurities is used to realize increased capacitance of an aluminum electrolytic capacitor, reduced height, and improved high frequency characteristics. In this aluminum plate, the total content of Fe in crystal/precipitate is 1 to 50% based on the original content, and the thickness of the aluminum plate 0.2 to 1 mm. In the formation of a capacitor anode, the aluminum plate is subjected to alternate current etching so as to leave a core part having an average thickness of 50 to 150 &#x3bc;m in the center part in the thickness-wise direction to increase the surface area, followed by anodic oxidation.

Aluminum plate for aluminum electrolytic capacitor electrode, aluminum electrolytic capacitor, and method for manufacturing aluminum electrolytic capacitor

An optical fiber comprising a core and a cladding region which covers an outer periphery of the core, having a zero-dispersion wavelength in a wavelength range of 1.4 &mgr;m to 1.65 &mgr;m, and being in a single mode in that zero-dispersion wavelength, wherein GeO is doped in the core in a quantity such that a relative refractive index difference of the core becomes not less than 1.8%, the cladding region includes first, second, and third cladding regions, and a refractive index of the second cladding region is smaller than those of the first cladding region and the third cladding region.

Optical fiber, optical fiber component and optical transmission method

A low-dispersion optical fiber provides both reduced chromatic dispersion in a used wavelength band and increased effective core area. The low-dispersion optical fiber is made by covering a center core ( ) with a first side core ( ), covering the first side core ( ) with a second side core ( ), and covering the second side core ( ) with a cladding ( ). When the maximum refractive index of the center core ( ) is written n1, the minimum refractive index of the first side core ( ) is written n2, the maximum refractive index of the second side core ( ) is written n3 and the refractive index of the cladding ( ) is written nc, then n1>n3>nc>n2 is satisfied. Relative refractive index differences &Dgr;1, &Dgr;2 and &Dgr;3 with respect to the cladding ( ) of the maximum refractive index of the center core ( ), the minimum refractive index of the first side core ( ) and the maximum refractive index of the second side core ( ) respectively are made 0.4%&lE;&Dgr;1&lE;0.7%, &minus;0.30%&lE;&Dgr;2&lE;&minus;0.05% and 0.2%&lE;&Dgr;3.

Low-dispersion optical fiber and optical transmission system using the low-dispersion optical fiber

A low-dispersion optical fiber provides both reduced chromatic dispersion in a used wavelength band and increased effective core area. The low-dispersion optical fiber is made by covering a center core ( ) with a first side core ( ), covering the first side core ( ) with a second side core ( ), and covering the second side core ( ) with a cladding ( ). When the maximum refractive index of the center core ( ) is written n the minimum refractive index of the first side core ( ) is written n , the maximum refractive index of the second side core ( ) is written n and the refractive index of the cladding ( ) is written nc, then n n nc>n is satisfied. Relative refractive index differences &Dgr;1, &Dgr;2 and &Dgr;3 with respect to the cladding ( ) of the maximum refractive index of the center core ( ), the minimum refractive index of the first side core ( ) and the maximum refractive index of the second side core ( ) respectively are made 0.4%&lE;&Dgr;1&gE;0.7%, &minus;0.30%&lE;&Dgr;2&lE;&minus;0.05% and 0.2%&lE;&Dgr;3.

An optical fiber, capable of generating by means of nonlinear phenomena, white light in adequately broadened wavelength bands at both sides of a pumping optical pulse that is input, and stabilizing the polarized conditions. The fiber is formed by covering a core with a first cladding, and covering the first cladding with a second cladding, where the second cladding has a refractive index greater than that of the first cladding, but lower than that of the core. Stress-applying parts are provided inside the second cladding so as to sandwich the core from both sides to form a polarization-maintaining optical fiber. The shortest distance between the stress-applying parts is made 2.3 times or more the mode field diameter for the wavelength of the pumping optical pulse.

Optical fiber

The present invention provides an optical fiber which has negative dispersion and negative dispersion slope in a wavelength band in use, and can carry out single-mode operation in which distortion due to the non-linear phenomenon can be suppressed so as to be suitable for wavelength multiplexed optical transmissions. When the relative index differences of center core ( ), first side core ( ), second side core ( ), and inner cladding ( ) from the silica level are &Dgr;1, &Dgr;2, &Dgr;3, and &Dgr;4, l.7%&lE;&Dgr;1, &Dgr;2&lE;&minus;0.3%, 0.25%&lE;&Dgr;3, and &Dgr;4<0. Furthermore, the value A, determined by dividing the diameter a1 of the center core by the diameter a2 of the first side core , is set to 0.15&lE;A&lE;0.2, and the value B, determined by dividing the diameter a3 of the second side core by the diameter a2 of the first side core , is set to 1<B&lE;2. By such an arrangement, the absolute values of the negative dispersion and negative dispersion slope in a wavelength band of 1.55 &mgr;m can be made large, and in addition, light is confined within the core by the second side core ( ), the effective core sectional area is made larger, and inner cladding ( ) is provided, whereby the effective cut-off wavelength is shortened.

Optical fiber and optical transmission line using the same

The present invention relates to a dispersion shifted optical fiber having zero dispersion at a wavelength band of 1.5 &mgr;m, which suppresses an increase of transmission loss and an increase of polarization mode dispersion when carrying out fiber drawing. An optical fiber according the invention is provided with the first core (refractive index n,.), the second core (refractive index n,), the first clad (refractive index n,) and second clad (refractive index n,) in this order from the center to outside, wherein the abovementioned refractive indexes are in a relationship of n,>n,>n,>n,, Ge which is at a ratio of 0.4 to 1.0% for the value of relative refractive index difference with respect to the second clad is doped on the first core, which is at a ratio of 0.1 to 0.5% for the value of relative refractive index difference with respect to the second clad is doped on the second core as in the above, and the second clad is SiO,, which has a thickness from 1 &mgr;m or more to 40 &mgr;m or less.

Dispersion shifted optical fiber

An information recording/reproducing method is disclosed for an information recording/reproducing apparatus including a recording medium having a disk-like shape, a unit for rotating the recording medium at a constant angular velocity, a unit for recording code information so that the bit length of the code information becomes approximately constant with respect to a radial position on the recording medium, a unit for modulating the code information to be recorded to form a modulated signal, and a recording unit for forming in the recording medium a localized recording region having a different physical property with respect to an unrecorded region, the recording unit being controlled by the modulated signal so that the code information is recorded to correspond to the edge of the recording region, wherein the bit rate of the code information to be recorded changes depending on a location on the recording medium, and a part of each of a recording characteristic of the apparatus and a reproducing characteristic of the apparatus is changed in accordance with a location on the recording medium.

Optical recording method employing pit edge recording on recording

Growing community of inventors

Tokyo, Japan

Shinichi Arai