公开(公告)号：US20240335578A1

公开(公告)日：2024-10-10

申请号：US18574348

申请日：2021-07-02

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Tomohiro TANIGUCHI ,  Ayako IWAKI ,  Satoshi NARIKAWA ,  Takahito KIRIHARA ,  Kazuhide NAKAJIMA ,  Takashi MATSUI ,  Nobutomo HANZAWA ,  Yuto SAGAE ,  Chisato FUKAI ,  Hitoshi SESHIMO ,  Ryuji YAMAMOTO ,  Asuka MIYAKE

IPC: A61L2/10 ,  A61L2/24 ,  B66B1/46

CPC classification number: A61L2/10 ,  A61L2/24 ,  A61L2202/11 ,  A61L2202/14 ,  B66B1/46

Abstract: An object of the present invention is to provide an ultraviolet light irradiation system that is easy to operate and can avoid degradation of a material due to ultraviolet light. An ultraviolet light irradiation system according to the present invention includes: one ultraviolet light source unit 11 that generates ultraviolet light; an irradiation unit 13 that irradiates a desired portion (irradiation portion ste) with the ultraviolet light in a limited manner; an optical fiber 14 that propagates the ultraviolet light from the ultraviolet light source unit 11 to the irradiation unit 13; a sensing unit 16 that monitors a state of the irradiation portion ste and outputs the state as monitoring information; and an irradiation control unit 15 that controls output of the ultraviolet light from the ultraviolet light source unit 11 on the basis of the monitoring information.

公开(公告)号：US20230270898A1

公开(公告)日：2023-08-31

申请号：US18018038

申请日：2020-10-23

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takashi MATSUI ,  Kazuhide NAKAJIMA ,  Nobutomo HANZAWA ,  Yuto SAGAE ,  Chisato FUKAI ,  Ayako IWAKI ,  Tomohiro TANIGUCHI ,  Kazutaka HARA ,  Atsuko KAWAKITA

IPC: A61L2/10 ,  A61L9/20

CPC classification number: A61L2/10 ,  A61L9/20 ,  A61L2202/11 ,  A61L2202/15

Abstract: An object of the present invention is to provide an ultraviolet light irradiation system and a decontamination method that can perform decontamination economically without any input from a user.
The ultraviolet light irradiation system forms a linear or planar ultraviolet light irradiation space by spatially bundling a plurality of ultraviolet light beams with high energy density or moving the ultraviolet light with high energy density at high speed. The ultraviolet light irradiation system can decontaminate a human body and clothing simply by passing through the space. Further, since the ultraviolet light irradiation system performs decontamination in the space, bacteria and viruses emitted from a carrier are not passed through the space.

公开(公告)号：US20220365282A1

公开(公告)日：2022-11-17

申请号：US17764239

申请日：2019-10-08

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yoko YAMASHITA ,  Masaki WADA ,  Takashi MATSUI ,  Kazuhide NAKAJIMA

IPC: G02B6/293 ,  G02B6/38

Abstract: An object of the present invention is to provide a core position recognition method, a connection method, and a connection apparatus that can simplify connection operations, and reduce rotational displacement and positional displacement. The connection apparatus according to the present invention includes a function capable of acquiring the rotation amount of an MCF during the bonding/fixing step. Specifically, the connection apparatus of the present invention uses an MCF with lines drawn on a side surface thereof, thereby recognizing the rotation amount of the MCF from the side surface, and calculating the absolute positions of the cores. The connection apparatus according to the present invention can recognize the absolute position s of the cores from a side image of an MCF in a state in which the MCF has been rotated. By forming a waveguide on a glass substrate serving as a connection destination so as to match the absolute positions of the cores, the rotational and positional displacements of the MCF can be eliminated, thus making it possible to reduce the connection loss.

公开(公告)号：US20220337025A1

公开(公告)日：2022-10-20

申请号：US17762399

申请日：2019-09-26

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Shinichi AOZASA ,  Taiji SAKAMOTO ,  Kazuhide NAKAJIMA ,  Masaki WADA

IPC: H01S3/23 ,  H01S3/067

Abstract: An objective of the present invention is to provide an optical amplifier having a cladding excitation configuration that improves amplification efficiency. The optical amplifier includes an optical amplification unit 36 in which n (n is a natural number equal to or greater than 2) amplification fibers 34 that optically amplify signal light propagating through cores with excitation light supplied to claddings and n−1 optical input/output units 35 that input/output the signal light to/from the cores and the outside of the amplification fibers 34 are connected in series such that the amplification fibers 34 and the optical input/output units 35 are disposed in an alternating manner, an excitation light generator 31 that outputs the excitation light in multi-mode, and optical multiplexer/demultiplexers 33 that cause the excitation light from the excitation light generator 31 that has been divided into two light beams to be incident on the claddings of the amplification fibers 34 disposed at both ends of the optical amplification unit 36 and cause the signal light to be input to/output from the cores of the amplification fibers 34 disposed at both ends of the optical amplification unit 36.

公开(公告)号：US20220337020A1

公开(公告)日：2022-10-20

申请号：US17760713

申请日：2019-09-26

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Shinichi AOZASA ,  Taiji SAKAMOTO ,  Kazuhide NAKAJIMA ,  Masaki WADA

IPC: H01S3/094 ,  H01S3/067 ,  H01S3/16

Abstract: An object is to provide an optical amplifier with a cladding pumped configuration that improves amplification efficiency. The optical amplifier according to the present invention includes a pump light conversion fiber 11 that converts first pump light L1 with a first wavelength propagating in a cladding into second pump light L2 with a second wavelength, an amplification fiber 13 that is connected to the pump light conversion fiber 11 and optically amplifies signal light Ls with the second pump light L2 supplied to the cladding from the pump light conversion fiber 11, and an oscillator 12 that causes the second pump light L2 to be reflected on two reflectors 15 and to reciprocate within the claddings of the pump light conversion fiber 11 and the amplification fiber 13 to cause laser oscillation of the second pump light L2.

公开(公告)号：US20220337016A1

公开(公告)日：2022-10-20

申请号：US17760697

申请日：2019-09-26

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Shinichi AOZASA ,  Taiji SAKAMOTO ,  Kazuhide NAKAJIMA ,  Masaki WADA

IPC: H01S3/067

Abstract: An objective is to provide an optical amplifier having a core excitation configuration that improves amplification efficiency. An optical amplifier according to the present invention includes an excitation light conversion fiber 11 that absorbs first excitation light L1 propagating in a cladding and having a first wavelength and emits, into a core, spontaneous emission light having a second wavelength, an oscillator 12 for causing the spontaneous emission light to be reflected on two reflectors 15 to reciprocate the light within the core of the excitation light conversion fiber 11 and laser-oscillating second excitation light L2 having the second wavelength, and an amplification fiber 13 that is connected to the excitation light conversion fiber 11 and amplifies signal light with the second excitation light L2 supplied from the excitation light conversion fiber 11 to the core.

公开(公告)号：US20180321439A1

公开(公告)日：2018-11-08

申请号：US15772263

申请日：2016-11-17

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

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

IPC: G02B6/02 ,  G02B6/032

Abstract: A photonic crystal fiber according to the present invention has a plurality of holes arranged in the optical fiber along a longitudinal direction, in which the holes are arranged 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 that a wide core area can be obtained while the number of modes that can be propagated is limited to several. Moreover, in a high-power optical transmission system according to the present invention, the amount of axis misalignment between the central axis of a laser oscillator and the central axis of the photonic crystal fiber is less than or equal to a certain amount.

公开(公告)号：US20250105578A1

公开(公告)日：2025-03-27

申请号：US18833531

申请日：2022-02-17

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Taiji SAKAMOTO ,  Ryota IMADA ,  Shinichi AOZASA ,  Kazuhide NAKAJIMA

IPC: H01S3/067 ,  H01S3/094

Abstract: An amplification optical fiber according to the present disclosure is an amplification optical fiber doped with a rare earth element, the amplification optical fiber including: a first cladding enclosing cores of the amplification optical fiber; and a second cladding enclosing the first cladding, in which the two or more cores are disposed inside the first cladding in a cross section of the amplification optical fiber, and a core cladding ratio Rcc, which is a ratio of a sum of areas of the two or more cores to a sum of areas of the two or more cores and the first cladding in the cross section of the amplification optical fiber, is 0.0095

公开(公告)号：US20240102886A1

公开(公告)日：2024-03-28

申请号：US18039600

申请日：2020-12-11

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Nobutomo HANZAWA ,  Takashi MATSUI ,  Yuto SAGAE ,  Kazuhide NAKAJIMA

IPC: G01M11/00 ,  C03C13/04

CPC classification number: G01M11/33 ,  C03C13/04 ,  C03C2213/00

Abstract: An object of the present invention is to provide an evaluation method and an evaluation device for easily determining whether or not a structural parameter of a multi-core fiber satisfies a desired connection loss value (a specification). The evaluation method according to the present invention includes a step of measuring center coordinates of each core with the center coordinates when a clad is approximated by a circle as an origin in an observed cross-sectional structure of the multi-core fiber to be objected, obtaining a length of a line segment connecting the origin and the center of each core and an angle formed by two line segments connecting the origin and two adjacent cores, and judging whether or not a desired connection loss characteristic is satisfied on the basis of whether or not the values satisfy a predetermined determination formula.

公开(公告)号：US20240007189A1

公开(公告)日：2024-01-04

申请号：US18021991

申请日：2020-08-21

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yuto SAGAE ,  Kazuhide NAKAJIMA ,  Takashi MATSUI ,  Taiji SAKAMOTO ,  Ryota IMADA

IPC: H04B10/291 ,  H04B10/25

CPC classification number: H04B10/2916 ,  H04B10/25 ,  G02B6/02042

Abstract: An object of the present invention is to provide an optical transmission system capable of satisfying XT required by a modulation system even if there is an inter-core loss difference in an MCF.
An optical transmission system of the present invention includes a multi-core optical fiber having a plurality of core regions and having different losses between at least two cores, a forward excitation light source and a multiplexing unit for allowing Raman amplification excitation light to be incident on each core of the multi-core optical fiber in the same direction as signal light, and a backward excitation light source and a multiplexing unit for allowing Raman amplification excitation light to be incident on each core of the multi-core optical fiber in a direction opposite to the signal light, wherein an intensity ratio of the forward excitation light to the backward excitation light is controlled (a ratio of power of excitation light is set to a predetermined value) such that crosstalk (XT) fluctuation between cores is reduced.