公开(公告)号：US20230042437A1

公开(公告)日：2023-02-09

申请号：US17791930

申请日：2020-02-19

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yoko YAMASHITA ,  Kazuhide NAKAJIMA ,  Takashi MATSUI

IPC: H01S3/067

Abstract: An object of the present disclosure is to allow gain compensation with a simple configuration without adding a new device to the outside. The present disclosure discloses a rare earth doped fiber including a core doped with a rare earth and a cladding region around the core, wherein one or more cavities are provided inside the core, and at least one of the cavities are provided along a longitudinal direction of the rare earth doped fiber.

公开(公告)号：US20220003920A1

公开(公告)日：2022-01-06

申请号：US17294892

申请日：2019-11-08

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takashi MATSUI ,  Kazuhide NAKAJIMA

IPC: G02B6/02 ,  G02B27/00

Abstract: It is an object of the present invention to provide a multicore optical fiber, a design method for the multicore optical fiber and an optical transmission method using the multicore optical fiber including four cores having a standard cladding diameter of 125±1 μm for an existing single mode optical fiber covering several thousands of kilometers of transmission. The multicore optical fiber according to the present invention disposes two-stage claddings with different refractive indices around each core, and designates as a predetermined range, a core radius a1, a radius a2 of a first cladding region surrounding each core, specific refractive index Δ1 relative to the core of the first cladding region and a specific refractive index Δ2 relative to the core of a second cladding region including four cores and the first cladding region.

公开(公告)号：US20180341104A1

公开(公告)日：2018-11-29

申请号：US15771040

申请日：2016-11-17

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takashi MATSUI ,  Kazuhide NAKAJIMA ,  Kyozo TSUJIKAWA ,  Fumihiko YAMAMOTO

IPC: G02B27/00 ,  G02B6/02

Abstract: An optical fiber design method according to the present invention is a design method of a photonic crystal fiber having a plurality of holes arranged in the optical fiber along a longitudinal direction, in which a required effective cross-sectional area is calculated from a light wavelength, a transmission distance, and output power such that, in a cross section, a hole ratio which is an area of the holes per unit area is larger in a central side than in an outer side in a portion corresponding to a cladding, and a fiber structure (hole diameter and hole interval) corresponding to the effective cross-sectional area is calculated.

公开(公告)号：US20180172902A1

公开(公告)日：2018-06-21

申请号：US15563988

申请日：2016-03-22

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takashi MATSUI ,  Kyozo TSUJIKAWA ,  Fumihiko YAMAMOTO ,  Nobutomo HANZAWA

IPC: G02B6/02

CPC classification number: G02B6/02328 ,  G02B6/02009 ,  G02B6/02309 ,  G02B6/02314 ,  G02B6/02347

Abstract: An object of the present invention is to provide a structure of an optical fiber capable of satisfying desired requirements of an output power, a propagation distance, and a beam quality. In the design of the PCF of the present invention, the PCF has air holes having diameters d and intervals Λ in an overlapping region where a region of Aeff of a desired value or more and a cutoff region in a desired higher-order mode overlap each other on a graph where the horizontal axis represents d/Λ and the vertical axis represents Λ, so that it is possible to sufficiently cut off the mode which is the desired higher-order mode or more, and thus, it is possible to select a region where the Aeff is large.