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：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：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.

公开(公告)号：US20230390436A1

公开(公告)日：2023-12-07

申请号：US18032514

申请日：2020-10-21

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

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

IPC: A61L2/10

CPC classification number: A61L2/10 ,  A61L2202/11

Abstract: An object of the present invention is to provide an ultraviolet light irradiation system and an ultraviolet light irradiation method which are not limited in an ultraviolet light irradiation region and can be introduced economically. The present ultraviolet light irradiation system is a system configured to connect a single ultraviolet light source part and an irradiation part installed in the vicinity of an object place to be sterilized or the like by the optical cable formed by bundling a plurality of optical fibers (the single-core or the multi-core) or the multi-core optical fiber. Since the optical fiber is very thin and does not require power supply for transmitting the ultraviolet rays, even in a fine place where a person or a robot cannot enter, the ultraviolet light can be irradiated by laying the optical fiber or the optical cable.

公开(公告)号：US20230280525A1

公开(公告)日：2023-09-07

申请号：US18024074

申请日：2020-09-04

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

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

IPC: G02B6/028 ,  G02B6/02

CPC classification number: G02B6/0288 ,  G02B6/02042

Abstract: The present disclosure relates to a multi-core optical fiber including:
M (where M is a positive integer of 1 or larger) group(s) each consisting of N (where N is a positive integer of 2 or larger) core regions linearly arranged in a cross section; a cladding region that surrounds the plurality of core regions and has a refractive index lower than any of the plurality of core regions; and a coating region that surrounds the cladding region, wherein the plurality of core regions are arranged in line symmetry with respect to both imaginary lines orthogonal to each other at a center of the cladding region, a diameter of the cladding region is 180 μm or less, and a diameter of the coating region is 235 μm or more and 265 μm or less.

公开(公告)号：US20230163554A1

公开(公告)日：2023-05-25

申请号：US17913097

申请日：2020-03-30

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Shinichi AOZASA ,  Yoko YAMASHITA ,  Takashi MATSUI ,  Kazuhide NAKAJIMA ,  Taiji SAKAMOTO ,  Nobutomo HANZAWA ,  Noriyuki ARAKI ,  Ryota IMADA ,  Yuto SAGAE

IPC: H01S3/067 ,  G02B6/32 ,  G02B3/08

CPC classification number: H01S3/06754 ,  G02B3/08 ,  G02B6/32 ,  H01S3/1608

Abstract: An object of the present disclosure is to implement a clad-excitation rare-earth-added optical fiber amplifier with a high light-to-light conversion efficiency. The present disclosure is an optical fiber amplifier having, in a longitudinal direction of a rare-earth-added optical fiber, a light collection structure that collets an excitation light, which propagates through a clad portion, into a core portion.

公开(公告)号：US20220294536A1

公开(公告)日：2022-09-15

申请号：US17634193

申请日：2019-08-19

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

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

IPC: H04B10/61

Abstract: An objective of the present invention is to provide an optical communication system and an optical communication method that can reduce even a delay generated in processing of obtaining a transfer function for correcting distortion in digital coherent transmission. In the optical communication system according to the present invention, pilot data for estimating a transfer function for a transmission channel is transmitted through a transmission channel with a short transmission delay time, a transfer function of the transmission channel is estimated before receiving transmission data, and the transfer function is applied to other transmission channels.