公开(公告)号：US12092879B2

公开(公告)日：2024-09-17

申请号：US17788848

申请日：2020-12-16

Applicant: Fujikura Ltd.

Inventor： Katsuhiro Takenaga ,  Yusuke Sasaki ,  Masaki Ohzeki

IPC: G02B6/38 ,  G02B6/02 ,  G02B6/44

CPC classification number: G02B6/3885 ,  G02B6/02042 ,  G02B6/4429

Abstract: A multicore fiber includes: a cladding; a center core at a center of the cladding; and seven or more outer cores disposed at rotationally asymmetric positions on a circumference centered at the center of the cladding. Angles formed by adjacent ones of lines connecting the center core and respective ones of the outer cores are all 60° or less.

公开(公告)号：US11960120B2

公开(公告)日：2024-04-16

申请号：US17633034

申请日：2021-02-22

Applicant: FUJIKURA LTD.

Inventor： Masaki Ohzeki ,  Katsuhiro Takenaga

IPC: G02B6/255 ,  G02B6/02 ,  G06T7/70

CPC classification number: G02B6/2555 ,  G02B6/02042 ,  G06T7/70 ,  G02B6/255

Abstract: A method for aligning multicore fiberS that has three or more cores disposed on a circumference centered on a central axis of a clad includes: capturing a first set of images of side surfaces of each of the pair of multicore fibers before and after rotating each of the pair of multicore fibers by P° a number of times (N) rounded up so that N=360/P; determining, for each of the pair of multicore fibers, a similarity between an image of the first set of images before a rotation by P° and an image of the first set of images after the rotation by P° for each of the N times the multicore fiber is rotated by P°; determining specific relative rotation positions of the pair of multicore fibers in which a cross-correlation becomes highest; and rotating at least one of the pair of multicore fibers.

公开(公告)号：US20230382779A1

公开(公告)日：2023-11-30

申请号：US18246919

申请日：2022-02-18

Applicant: Fujikura Ltd.

Inventor： Ryohei Fukumoto ,  Katsuhiro Takenaga

IPC: C03B37/012 ,  C03B37/027

CPC classification number: C03B37/01222 ,  C03B37/01251 ,  C03B37/027 ,  C03B2203/34

Abstract: A multi-core optical fiber preform includes: a rod-shaped main cladding body having one or more main inner holes; main core rods inserted into the one or more main inner holes; and a tip continuously-installed portion disposed at one end of the rod-shaped main cladding body and including a glass rod having no core rod or having one core rod.

公开(公告)号：US10656327B2

公开(公告)日：2020-05-19

申请号：US16076610

申请日：2016-12-05

Applicant: FUJIKURA LTD.

Inventor： Shota Saito ,  Katsuhiro Takenaga

IPC: G02B6/02 ,  G02B6/028 ,  G02B6/036

Abstract: An optical fiber that communicates in a predetermined communication band includes: a signal light propagation core that propagates light beams of up to (x+1)-th order LP mode, where x is an integer of two or more; and a coupler that propagates a light beam that is: coupled with a light beam of the (x+1)-th order LP mode propagating through the signal light propagation core, and suppressed from being coupled with light beams of up to the x-th order LP mode propagating through the signal light propagation core, wherein, mode coupling of the light beams of up to the x-th order LP mode propagating through the signal light propagation core is performed, and mode coupling between the light beam of the x-th order LP mode and the light beam of (x+1)-th order LP mode is suppressed.

公开(公告)号：US10101526B2

公开(公告)日：2018-10-16

申请号：US15569661

申请日：2016-04-26

Applicant: FUJIKURA LTD. ,  NATIONAL UNIVERSITY CORPORATION HOKKAIDO UNIVERSITY

Inventor： Yusuke Sasaki ,  Katsuhiro Takenaga ,  Kunimasa Saitoh

IPC: G02B6/02 ,  G02B6/44 ,  G02B6/036

Abstract: A multicore fiber communicates using light up to an xth-order LP mode (where x is an integer of 1 or more) in a communication band. The multicore fiber includes: a plurality of cores; a clad that surrounds the plurality of cores and has a refractive index lower than refractive indexes of the plurality of cores; and a cover layer that covers the clad and has a refractive index higher than the refractive index of the clad. Each of the plurality of cores propagates light up to an (x+1)th-order LP mode. A core pitch is set to a distance where crosstalk of the light up to the xth-order LP mode becomes less than or equal to −40 dB/km and crosstalk of light of the (x+1)th-order LP mode becomes greater than or equal to −30 dB/km.

公开(公告)号：US10042114B2

公开(公告)日：2018-08-07

申请号：US15141945

申请日：2016-04-29

Applicant: FUJIKURA LTD. ,  NATIONAL UNIVERSITY CORPORATION HOKKAIDO UNIVERSITY

Inventor： Katsuhiro Takenaga ,  Shoichiro Matsuo ,  Yusuke Sasaki ,  Kunimasa Saitoh

IPC: G02B6/02 ,  G02B6/036

Abstract: A multicore fiber for communication 10 which allows propagation of an optical signal includes: a clad 12; a core 11a which is arranged in a center of the clad 12; and seven to ten cores 11b which are arranged at equal intervals surrounding the core 11a, and the cladding diameter is 230 μm, distances between centers of the mutually neighboring cores 11a and 11b are 30 μm or more, distances between the centers of the cores 11b and an outer peripheral surface of the clad 12 are 35 μm or more and a mode field diameter of light propagating in the cores 11a and 11b is 9 μm to 13 μm.

公开(公告)号：US20170235043A1

公开(公告)日：2017-08-17

申请号：US15501493

申请日：2016-02-10

Applicant: FUJIKURA LTD. ,  NATIONAL UNIVERSITY CORPORATION HOKKAIDO UNIVERSITY

Inventor： Yoshimichi Amma ,  Katsuhiro Takenaga ,  Yusuke Sasaki ,  Kunimasa Saitoh

IPC: G02B6/02

CPC classification number: G02B6/02042 ,  G02B6/02014

Abstract: No core is disposed at the lattice point of a triangular lattice of a first layer LY1. First cores 11a and 11b of the core elements 10a and 10b are disposed at the lattice points of a second layer LY2. A first core 11c of the core element 10c and the second core 21 are alternately disposed at the lattice points of a third layer LY3. In a fourth layer LY4, no core is disposed at six lattice points, and the first cores 11a and 11b of the core elements 10a and 10b are disposed at the other lattice points. The second cores 21 are adjacent to the lattice points of the fourth layer LY4, at which no core is disposed. The effective refractive indexes of the core elements adjacent to each other are different from each other.

公开(公告)号：US20160187576A1

公开(公告)日：2016-06-30

申请号：US15062530

申请日：2016-03-07

Applicant: FUJIKURA LTD. ,  NATIONAL UNIVERSITY CORPORATION HOKKAIDO UNIVERSITY

Inventor： Yusuke Sasaki ,  Katsuhiro Takenaga ,  Yoshimichi Amma ,  Kunimasa Saitoh

IPC: G02B6/02 ,  G02B6/028

CPC classification number: G02B6/02042 ,  G02B6/02219 ,  G02B6/028 ,  G02B6/0288 ,  G02B6/036

Abstract: In a C band and an L band, the effective refractive indices of light propagating through the cores 11 and 21 adjacent to each other are different from each other such that a magnitude of crosstalk of light of a highest-order LP mode commonly propagating through the cores 11 and 21 adjacent to each other between the cores 11 and 21 adjacent to each other becomes a peak at a bending diameter smaller than a diameter of 100 mm, and the core has a higher refractive index in a center portion than in an outer circumferential portion such that a differential mode group delay of the cores 11 and 12 is 700 picoseconds/km or less.

Abstract translation: 在C波段和L波段中，通过彼此相邻的芯11和21传播的光的有效折射率彼此不同，使得最高阶LP模式的光的串扰的大小通常传播通过 在彼此相邻的芯11和21之间彼此相邻的芯11和21在弯曲直径小于直径100mm的峰处，并且芯在中心部分具有比外周更高的折射率 使得芯11和12的差模组群延迟为700皮秒/ km或更小。

公开(公告)号：US09366807B2

公开(公告)日：2016-06-14

申请号：US14603488

申请日：2015-01-23

Applicant: FUJIKURA LTD.

Inventor： Shoji Tanigawa ,  Katsuhiro Takenaga

IPC: G02B6/00 ,  G02B6/02 ,  G02B6/036 ,  C03B37/012 ,  C03B37/027

CPC classification number: G02B6/02042 ,  C03B37/01222 ,  C03B37/02754 ,  C03B2201/02 ,  C03B2201/12 ,  C03B2201/20 ,  C03B2201/31 ,  C03B2203/22 ,  C03B2203/26 ,  C03B2203/34 ,  C03B2205/14

Abstract: Provided is a method of producing a preform 10P for a coupled multi-core fiber including: an arranging process P1 for arranging a plurality of core glass bodies 11R and a clad glass body 12R in such a way that the plurality of core glass bodies 11R are surrounded by the clad glass body 12R; and a collapsing process P2 for collapsing a gap between the core glass bodies 11R and the clad glass body 12R, wherein the respective core glass bodies 11R have outer regions 16 having a predetermined thickness from the periphery surfaces and made of silica glass undoped with germanium, and the clad glass body 12R is made of silica glass having a refractive index lower than a refractive index of the outer regions of the core glass bodies 11R.

公开(公告)号：US09252556B2

公开(公告)日：2016-02-02

申请号：US14441029

申请日：2013-10-31

Applicant: FUJIKURA LTD. ,  NIPPON TELEGRAPH AND TELEPHONE CORPORATION ,  OSAKA PREFECTURE UNIVERSITY PUBLIC CORPORATION ,  National University Corporation Shimane University

Inventor： Shoichiro Matsuo ,  Katsuhiro Takenaga ,  Kentaro Ichii ,  Hirotaka Ono ,  Kyouzou Tsujikawa ,  Makoto Yamada ,  Hiroji Masuda

IPC: H01S3/00 ,  H01S3/067 ,  G02B6/02 ,  G02B6/036 ,  H01S3/091

CPC classification number: H01S3/06754 ,  G02B6/02042 ,  G02B6/03605 ,  G02B6/03611 ,  H01S3/06729 ,  H01S3/06733 ,  H01S3/06737 ,  H01S3/091 ,  H01S3/094007 ,  H01S3/2383

Abstract: The first cladding 52 has a two-layer structure formed of a solid inner layer 62A passed through the center axis of the first cladding 52 and an outer layer 62B enclosing the inner layer 62A and the plurality of cores 51 with no gap. A refractive index n1 of the core 51 is provided higher than refractive indexes n2A and n2B of the inner layer 62A and the outer layer 62B, the refractive indexes n2A and n2B of the inner layer 62A and the outer layer 62B are provided higher than a refractive index n3 of the second cladding 53, and the refractive index n2A of the inner layer 62A is provided lower than the refractive index n2B of the outer layer 62B.

Abstract translation: 第一包层52具有由穿过第一包层52的中心轴线的实心内层62A和不间隙地包围内层62A和多个芯51的外层62B形成的两层结构。 芯体51的折射率n1比内层62A和外层62B的折射率n2A，n2B高，内层62A和外层62B的折射率n2A，n2B高于屈光度 第二包层53的折射率n3和内层62A的折射率n2A被设定为低于外层62B的折射率n2B。