公开(公告)号：US20190004246A1

公开(公告)日：2019-01-03

申请号：US15752809

申请日：2016-03-03

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

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

IPC: G02B6/02 ,  G02B6/42

CPC classification number: G02B6/02347 ,  B23K26/702 ,  G02B6/02 ,  G02B6/02314 ,  G02B6/02333 ,  G02B6/0288 ,  G02B6/42 ,  G02B6/4206

Abstract: An optical fiber that is a photonic crystal fiber in which a plurality of holes is arranged along a longitudinal direction of the optical fiber, having a predetermined bending radius R determined according to a transmission distance L of the optical fiber and optical power output from the optical fiber, and having an inter-hole distance Λ and a ratio d/Λ between a hole diameter d and the inter-hole distance Λ such that light of a predetermined number of modes is transmitted and a bending loss of the light of a fundamental mode with the predetermined bending radius R is equal to or smaller than a predetermined value.

公开(公告)号：US20250060213A1

公开(公告)日：2025-02-20

申请号：US18706667

申请日：2022-11-29

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION ,  THE UNIVERSITY OF TOKYO

Inventor： Nobutomo HANZAWA ,  Kazuhide NAKAJIMA ,  Takashi MATSUI ,  Hideaki MURAYAMA ,  Ryota WADA ,  Makito KOBAYAHSI

IPC: G01B11/16

Abstract: The present disclosure is a shape measurement system including: a multi-core optical fiber in which four or more cores are disposed in a part other than the center of a cross section; a strain distribution measurement device configured to measure a strain distribution of each of the cores in a longitudinal direction of the multi-core optical fiber; and an analysis device configured to calculate a shape of the multi-core optical fiber by using the strain distribution of the multi-core optical fiber.

公开(公告)号：US20250001036A1

公开(公告)日：2025-01-02

申请号：US18695310

申请日：2021-09-30

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

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

IPC: A61L9/20 ,  F24F8/167 ,  F24F8/22

Abstract: An object of the present invention is to provide an air conditioner unit that can fully demonstrate the sterilization effect on air with a large flow rate, even by a method of irradiating a filter and a coil with ultraviolet light. The air conditioner unit according to the present invention includes a filter 20 through which air passes, a plurality of optical fibers 16 arranged in such a manner that one ends thereof are close to a surface of the filter 20 and arranged at predetermined intervals, and a light source 30 that supplies ultraviolet light from the other end of each of the optical fibers 16. Since the intensity of the light is inversely proportional to the square of the distance from the light source, if the same sterilization effect is to be obtained, the shorter the irradiation distance, the smaller the irradiation intensity of the ultraviolet light can be. That is, by bringing the tips of the optical fibers close to the surface of the filter, the filter can be sterilized by an LED having a small output.

公开(公告)号：US20240418073A1

公开(公告)日：2024-12-19

申请号：US18706684

申请日：2022-11-29

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION ,  THE UNIVERSITY OF TOKYO

Inventor： Nobutomo HANZAWA ,  Kazuhide NAKAJIMA ,  Takashi MATSUI ,  Hideaki MURAYAMA ,  Ryota WADA

IPC: E21B47/001 ,  G01M5/00

Abstract: The present disclosure is a control system configured to: collect a strain distribution of an underwater structure connected to an above-water structure; and control at least one of the underwater structure and the above-water structure in accordance with the strain distribution.

公开(公告)号：US20240272375A1

公开(公告)日：2024-08-15

申请号：US18570431

申请日：2021-06-21

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yoshiteru ABE ,  Yoko YAMASHITA ,  Taiji SAKAMOTO ,  Takashi MATSUI ,  Kazuhide NAKAJIMA ,  Kazunori KATAYAMA

IPC: G02B6/38

CPC classification number: G02B6/3882

Abstract: An object of the present disclosure is to connect an optical fiber and an optical waveguide with a low loss. The present disclosure is an optical connector plug, including: an optical waveguide having two guide pin V-grooves engraved on one surface thereof and having a cross section of one or more cores appearing between cross sections of the guide pin V-grooves on one end face thereof; two guide pins separately arranged in the two guide pin V-grooves; a flat substrate so fixed as to tuck the two guide pins in the two guide pin V-grooves on the one surface of the optical waveguide; and a fixing member equipped with the optical waveguide, the two guide pins, and the flat substrate.

公开(公告)号：US20240142696A1

公开(公告)日：2024-05-02

申请号：US18277320

申请日：2021-02-17

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yoko YAMASHITA ,  Takayoshi MORI ,  Takashi MATSUI ,  Kazuhide NAKAJIMA

IPC: G02B6/02 ,  G02B27/00

CPC classification number: G02B6/02095 ,  G02B27/0012

Abstract: An objective of the present invention is to provide a mode conversion device capable of designing any coupling efficiency and full width at half maximum, and a design method therefor.
According to the present invention, a mode conversion device includes a long period grating at a core of an optical fiber through which light is able to propagate in at least two propagation modes. The long period grating satisfies a relationship of Expression C1, where a full width at half maximum FWHM is a wavelength band in which the coupling efficiency is a half of coupling efficiency of mode conversion at a center wavelength, C is coupling efficiency, Lc is a complete coupling length, Lg is a grating length, Λ is a grating pitch, and Δβ is a propagation constant difference between the two propagation modes at the center wavelength of a mode conversion target.







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公开(公告)号：US20240061168A1

公开(公告)日：2024-02-22

申请号：US18267917

申请日：2021-01-05

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yuto SAGAE ,  Takashi MATSUI ,  Kazuhide NAKAJIMA

IPC: G02B6/02

CPC classification number: G02B6/02042 ,  G02B6/021

Abstract: An object of the present invention is to achieve a low delay core applicable to a Master channel of a Master-Slave CPE (MS-CPE) transmission method with a general-purpose refractive index distribution structure.
An optical fiber according to the present invention is a single-mode optical fiber, and has an SI-type refractive index distribution structure, in which a clad region relative refractive index difference Δ (%) with respect to a core region refractive index, a radius a (μm) of the core region, and a group delay time difference Δτ between the Master channel and the Slave channel satisfy “Mathematical Expression 19” and “Mathematical Expression 20”, or



has a W-type refractive index distribution structure, in which a mode field diameter MFD is 9.5 to 10.1 μm, and a relative refractive index difference Δ1 (%) of a low refractive index layer with respect to a core, a relative refractive index difference Δ2 (%) of the clad region with respect to the core, the core radius a1, and the group delay time difference Δτ between the Master channel and the Slave channel satisfy “Mathematical Expression 41”.

公开(公告)号：US20240019323A1

公开(公告)日：2024-01-18

申请号：US18034899

申请日：2021-10-18

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION ,  THE UNIVERSITY OF TOKYO

Inventor： Takashi MATSUI ,  Kazuhide NAKAJIMA ,  Nobutomo HANZAWA ,  Ryota WADA ,  Hideaki MURAYAMA

IPC: G01L1/24

CPC classification number: G01L1/242

Abstract: An object of the present disclosure is to enable behavior of a linear structure in water to be estimated. The present disclosure is an apparatus that: expresses at least one parameter in a plurality of discrete values, and forecasts behavior of a linear structure by using each of the discrete values; acquires behavior of the linear structure detected using an optical fiber; calculates a likelihood between the forecasted behavior of the linear structure and the acquired behavior of the linear structure; updates at least one of the plurality of discrete values on the basis of the likelihood; and calculates behavior of the linear structure by using the updated plurality of discrete values.

公开(公告)号：US20230400625A1

公开(公告)日：2023-12-14

申请号：US18026359

申请日：2020-09-18

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yoko YAMASHITA ,  Takashi MATSUI ,  Kazuhide NAKAJIMA

IPC: G02B6/02 ,  G02B6/36

CPC classification number: G02B6/022 ,  G02B6/36

Abstract: An object is to provide an optical side input/output circuit that has wavelength selectivity and is easily disposed at multiple points in a transmission path, and an optical connector.
An optical side input/output circuit 301 according to the present invention includes: a grating portion 20 in which a fiber Bragg grating 21 that reflects light of a desired wavelength is formed in the core 51 of an optical fiber 50, the light of the desired wavelength being of light propagating in the core 51; and a tap portion 10 that is disposed at a stage before the grating portion 20 in the propagation direction of the light, and is provided with a tap waveguide 53 that outputs the light reflected by the grating portion 20 from a side surface of the optical fiber 50.

公开(公告)号：US20230358966A1

公开(公告)日：2023-11-09

申请号：US18026381

申请日：2020-09-18

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yoko YAMASHITA ,  Takashi MATSUI ,  Kazuhide NAKAJIMA

IPC: G02B6/34

CPC classification number: G02B6/34

Abstract: The present invention aims to provide an optical side input/output circuit that has wavelength selectivity and is easily disposed at multiple points in a transmission path, and an optical connector.
The optical side input/output circuit 301 includes: a tap portion 10 in which a tap waveguide 53 that outputs light of a higher-order mode from a side surface of an optical fiber 50 is formed, the light of the higher-order mode being of light propagating in the core 51 of the optical fiber 50; and a grating portion 20 that is located in a stage before the tap portion 10 in the propagation direction of the light, and has a grating 21 that converts light of a desired wavelength from a basic mode to the higher-order mode, the grating 21 being formed in the core 51 of the optical fiber 50.