公开(公告)号：EP3604243A1

公开(公告)日：2020-02-05

申请号：EP18771583.4

申请日：2018-03-08

申请人： Furukawa Electric Co., Ltd. ,  Nippon Telegraph and Telephone Corporation

发明人： ARAI, Shinichi ,  INABA, Harumi ,  MATSUMOTO, Shigeto ,  YAGI, Takeshi ,  AOZASA, Shinichi ,  TSUJIKAWA, Kyozo ,  NAKAJIMA, Kazuhide

IPC分类号： C03B37/012 ,  C03B37/014 ,  C03B37/027 ,  G02B6/02

摘要： An optical fiber manufacturing method includes placing, inside a glass pipe constituting a cladding portion, a first holding member, which is one of a pair of holding members made of glass and having a plurality of holes formed thereon, and a core rod, which includes a core forming portion serving as the core portion and includes a cladding forming portion constituting the cladding portion, in such a way that the core rod is supported by the first holding member; includes filling glass particles in the gap between the inner wall face of the glass pipe and the core rod; includes placing a second holding member of the pair of holding members inside the glass pipe and holding the core rod in a sandwiched manner in between the first holding member and the second holding member; includes sealing one end portion of the glass pipe and manufacturing an intermediate object; and includes manufacturing an optical fiber using the intermediate object. The bulk density of the first holding member and the second holding member is set to be within a predetermined range with reference to the bulk density of the filling portion filled with the glass particles, and the predetermined range is determined according to the permissible variation range for the core diameter in the longitudinal direction of the optical fiber.

公开(公告)号：EP3726196A1

公开(公告)日：2020-10-21

申请号：EP18887703.9

申请日：2018-12-14

申请人： FURUKAWA ELECTRIC CO., LTD.

发明人： ARAI, Shinichi ,  MATSUMOTO, Shigeto

IPC分类号： G01N3/00 ,  C03B37/12 ,  G01M11/00 ,  G01N3/08 ,  G02B6/02

摘要： To provide a method and device for screening an optical fiber core, and a method for manufacturing an optical fiber core that can suppress occurrence of damage in resin coating layers of optical fiber, a screening method applies a guaranteed tensile strain set as a guaranteed value to the optical fiber core with a resin coating layer. The method 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 smaller than the guaranteed tensile strain, 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 just for a predetermined time, and a strain releasing step of releasing the optical fiber core from the guaranteed tensile strain.

公开(公告)号：EP3940354A1

公开(公告)日：2022-01-19

申请号：EP20770067.5

申请日：2020-03-05

申请人： Furukawa Electric Co., Ltd.

发明人： HASEGAWA, Hideaki ,  TAMAOKA, Hiroyuki ,  YAGI, Takeshi ,  ARAI, Shinichi

IPC分类号： G01H9/00 ,  G01L1/24 ,  G01L11/02 ,  G01L5/00 ,  G02B6/00 ,  G02B6/02 ,  G02B6/04

摘要： 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 are included, and pressure applied to the sensor optical fiber is detected on a basis of intensity of the signal light received by the optical receiver. An optical transmission body including the sensor optical fiber and a transmission optical fiber connected to the sensor optical fiber and smaller in propagation loss than the sensor optical fiber may be included.

公开(公告)号：EP3950614A1

公开(公告)日：2022-02-09

申请号：EP20780062.4

申请日：2020-03-09

申请人： Furukawa Electric Co., Ltd.

发明人： TAKAHASHI, Masanori ,  MAEDA, Koichi ,  ARAI, Shinichi ,  SUGIZAKI, Ryuichi ,  TSUKAMOTO, Masayoshi

IPC分类号： C03B37/012 ,  G02B6/02

摘要： It is an object to provide a manufacturing method of a multicore fiber preform that improves the positioning accuracy of cores, reduces the degree of core being non-circular shape, and improves the flexibility in designing. In the manufacturing method of a multicore fiber preform, n pieces of first core rods in a cylindrical shape with a radius r1, a second core rod in a cylindrical shape with a radius R1, and a cladding in a cylindrical shape are prepared, points P11 to P1n are set at positions, distances of which are X11 to X1n, respectively, from a point a1 on straight lines dividing an end surface into n pieces to have an equal central angle, about the point a1 on the end surface of the cladding such that X1max-r1

公开(公告)号：EP4131804A1

公开(公告)日：2023-02-08

申请号：EP21776945.4

申请日：2021-03-17

申请人： FURUKAWA ELECTRIC CO., LTD.

发明人： TAKASAKA, Shigehiro ,  MAEDA, Koichi ,  AISO, Keiichi ,  ARAI, Shinichi ,  SUGIZAKI, Ryuichi ,  MUKASA, Kazunori ,  TSUCHIDA, Yukihiro ,  TAKAHASHI, Masanori

IPC分类号： H04B10/291 ,  G02B6/02 ,  G02B6/036 ,  H01S3/067 ,  H01S3/10

摘要： An optical amplifying fiber includes at least a single core portion doped with a rare-earth element; an inner cladding portion that encloses the core portion and that has a lower refractive index than the maximum refractive index of the core portion; and an outer cladding portion that encloses the inner cladding portion and that has a lower refractive index than the refractive index of the inner cladding portion. The inner cladding portion includes a plurality of air bubbles.