公开(公告)号：US20220352980A1

公开(公告)日：2022-11-03

申请号：US17619610

申请日：2019-06-18

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Hidenobu HIROTA ,  Takui UEMATSU ,  Hiroyuki IIDA ,  Naotsugu AMBE

IPC: H04B10/079

Abstract: The present disclosure has an object to provide a technique for enabling a communication state to be confirmed not in a communication building but in a work site, and to provide a technique for enabling correct splicing between optical cables to be confirmed before fusion splicing. The present disclosure is a communication apparatus identification device 4 including an optical fiber bent portion 42 obtained by, when a portion of optical fibers to which communication apparatuses (the OLT 1-2 and the ONU 2) for which appropriateness of connection is to be determined are connected on opposite ends is bent, bending a portion of the optical fibers in a vicinity of a clearance provided between the optical fibers, the clearance having a range in which the communication apparatuses for which appropriateness of connection is to be determined can communicate with each other, and a MAC address analysis unit 43 that analyzes communication light leaked out of the bent portion of the optical fibers in the vicinity of the clearance to acquire identification numbers (MAC addresses) of the communication apparatuses for which appropriateness of connection is to be determined.

公开(公告)号：US20220228947A1

公开(公告)日：2022-07-21

申请号：US17595930

申请日：2019-06-03

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Hiroyuki IIDA ,  Sachi TSUJIMURA ,  Hidenobu HIROTA ,  Takui UEMATSU ,  Naotsugu AMBE

IPC: G01M11/02

Abstract: An object is to provide a determination device that determines a state of a terminal end portion of a coated optical fiber at any location of the coated optical fiber. Reflection of test light varies in a reflection amount at each wavelength depending on a situation of the terminal end portion of the coated optical fiber. In other words, if the magnitude of the reflection amount at each wavelength can be known, the situation of the terminal end portion of the coated optical fiber can be estimated. The determination device according to the present invention is configured to make test light having a plurality of wavelengths incident from the optical fiber side and determine the test light based on a light intensity ratio of each reflected light beams reflected at the terminal end. In addition, reflection of test light varies in return loss at each wavelength depending on a situation of the terminal end portion of the coated optical fiber. If Rayleigh backscattered light can also be measured when measuring a reflection amount, the return loss can be known for each wavelength, and the situation of the terminal end portion of the coated optical fiber can be estimated from the result. The determination device according to the present invention is configured to make test light having a plurality of wavelengths incident from the optical fiber side and determine the test light based on a return loss at the terminal end.

公开(公告)号：US20210262892A1

公开(公告)日：2021-08-26

申请号：US17252311

申请日：2019-06-12

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Hiroyuki IIDA ,  Tetsuya MANABE ,  Yusuke KOSHIKIYA ,  Hidenobu HIROTA ,  Takui UEMATSU

IPC: G01M11/00 ,  H04B10/071

Abstract: An object of the present disclosure is to provide a frequency division multiplexing coherent OTDR, a test method, a signal processing apparatus, and a program that can maintain, even in a case where a DFB laser is used, a spatial resolution equivalent to a spatial resolution achieved when a fiber laser or an external resonant laser is used. An OTDR according to the present disclosure includes a light incidence unit configured to change an optical frequency of light from a light source by a predetermined frequency interval at a predetermined time interval to generate test light pulses and cause the test light pulses to sequentially enter a fiber under test, a light reception unit configured to use the light from the light source as local light to coherently detect backscattered light from the fiber under test to acquire a received signal, and a computation unit configured to separate the received signal into signals with frequencies obtained by changing the optical frequency by the predetermined frequency interval, square amplitudes of the signals resulting from frequency separation to generate square values, perform Wiener filter processing on the square values, compensate values resulting from the Wiener filter processing for delay time when the test light pulses are caused to enter the fiber under test, and calculate an arithmetic mean of the compensated values.

公开(公告)号：US20230280536A1

公开(公告)日：2023-09-07

申请号：US18016438

申请日：2020-07-21

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Tatsuya FUJIMOTO ,  Hidenobu HIROTA ,  Takui UEMATSU ,  Tomohiro KAWANO ,  Hiroyuki IIDA ,  Ryo KOYAMA ,  Tetsuya MANABE ,  Kazunori KATAYAMA

IPC: G02B6/28

CPC classification number: G02B6/2821

Abstract: An object of the present disclosure is to provide an optical coupling device capable of controlling a coupling index of optical coupling between two optical fibers for coupling. An optical coupling device of the present disclosure includes two optical fibers for coupling having a core and a clad, and a refractive index variable member to change the refractive index by irradiation with light between the two optical fibers for coupling.

公开(公告)号：US20220342153A1

公开(公告)日：2022-10-27

申请号：US17762252

申请日：2019-10-02

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takui UEMATSU ,  Hidenobu HIROTA ,  Hiroyuki IIDA ,  Takashi EBINE

IPC: G02B6/28

Abstract: A manufacturing method of an optical splitter of the present disclosure includes: performing first processing that involves mounting a coated optical fiber on a jig configured to store the coated optical fiber, and polishing the coated optical fiber together with the jig until reaching a vicinity of a core of the coated optical fiber or the core of the coated optical fiber; performing second processing that involves applying a refractive index matching material having a refractive index lower than a refractive index of the core of the coated optical fiber onto a polished face of the coated optical fiber on the jig polished in the first processing or onto a polished face of an optical waveguide circuit having been polished in advance until reaching a vicinity of a core or reaching the core, and then bonding the polished faces to each other; and performing third processing that involves positionally aligning the polished faces bonded with each other in the second processing to move the jig or the optical waveguide circuit to a position at which a desired splitting ratio is obtained.

公开(公告)号：US20220171137A1

公开(公告)日：2022-06-02

申请号：US17420954

申请日：2020-01-06

Applicant: Nippon Telegraph and Telephone Corporation

Inventor： Hidenobu HIROTA ,  Takui UEMATSU ,  Hiroyuki IIDA ,  Naotsugu AMBE

IPC: G02B6/38 ,  F21V8/00

Abstract: An object of the present invention is to provide, in a local-light coupling technique for improving efficiency of work, an optical fiber local-light coupling apparatus configured to hardly affect communication between an OLT and an ONU while causing light to leak from a coated optical fiber in such an amount that makes it possible to confirm a communication state.
The optical fiber local-light coupling apparatus according to the present invention includes a first jig including a concave portion curved in a longitudinal direction with respect to a coated optical fiber, and a probe configured to receive leakage light leaking from the coated optical fiber being bent; a second jig including a convex portion curved in the longitudinal direction with respect to the coated optical fiber, the convex portion being configured to sandwich the coated optical fiber between the convex portion and the concave portion of the first jig; a pressing unit configured to apply pressing force in a direction in which the concave portion of the first jig and the convex portion of the second jig approach each other to form a bend in the coated optical fiber; and a reflective film configured to cover a surface of the concave portion of the first jig except for a leakage light passage portion through which, among the leakage light, reception leakage light to be received by the probe passes, and reflect and return the leakage light other than the reception leakage light to the coated optical fiber.

公开(公告)号：US20220128765A1

公开(公告)日：2022-04-28

申请号：US17427848

申请日：2020-01-22

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takui UEMATSU ,  Hidenobu HIROTA ,  Hiroyuki IIDA ,  Naotsugu AMBE

IPC: G02B6/28

Abstract: An object of the present invention is to provide a versatile optical fiber lateral output device that can deal with various types of optical fiber core wires. An optical fiber input-output device according to the present invention includes: a first jig 11 including a recess portion 22 and an optical input-output means 51; a second jig 12 including a projection portion 23 and a guide groove 24; and a pressing unit 14 configured to apply a pressing force in a direction in which the recess portion 22 of the first jig 11 and the projection portion 23 of the second jig 12 approach each other so as to bend an optical fiber core wire 100. Letting R1 be a curvature radius of the recess portion 22 of the first jig 11, θ1 be a central angle of the recess portion 22, R2 be a curvature radius of the projection portion 23 of the second jig 12, and θ2 be a central angle of the projection portion 23, R2≤R1 and θ2≤θ1 are satisfied.

公开(公告)号：US20220066101A1

公开(公告)日：2022-03-03

申请号：US17422911

申请日：2020-01-06

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takui UEMATSU ,  Hiroyuki IIDA ,  Hidenobu HIROTA ,  Naotsugu AMBE

IPC: G02B6/28 ,  G02B6/38

Abstract: An object is to provide a highly versatile local-light detection apparatus for an optical fiber capable of supporting various types of coated optical fibers.
A local-light detection apparatus for an optical fiber according to the present invention includes a first jig including a recess curved in a longitudinal direction of a coated optical fiber and an optical input and output device configured to make light incident on the coated optical fiber in which a bend is formed and to receive light leaking from the coated optical fiber, a second jig including a protrusion curved in the longitudinal direction of the coated optical fiber, the protrusion being configured to sandwich the coated optical fiber between the recess of the first jig and the protrusion, a presser configured to apply a pressing force in a direction in which the recess of the first jig and the protrusion of the second jig approach each other and to form the bend in the coated optical fiber, and fiber guides disposed at both ends of the recess of the first jig in the longitudinal direction of the coated optical fiber, and to arrange the coated optical fiber on a predetermined path on the recess of the first jig regardless of a diameter of the coated optical fiber when the presser forms the bend in the coated optical fiber.

公开(公告)号：US20210239567A1

公开(公告)日：2021-08-05

申请号：US16973396

申请日：2019-06-04

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Hiroyuki IIDA ,  Tetsuya MANABE ,  Yusuke KOSHIKIYA ,  Hidenobu HIROTA ,  Takui UEMATSU

IPC: G01M11/00 ,  G01M11/02 ,  A61B5/024 ,  H04B10/071

Abstract: An object of the present invention is to provide an optical pulse test apparatus that can test an optical fiber cable at once in a short period of time. The optical pulse test apparatus according to the present invention includes: an optical pulse signal generation unit 11 that emits an optical pulse with a width that is n times as large as a pulse width T corresponding to desired spatial resolution; a light reception unit 12 that receives reflected light and back-scattered light from n FUTs; an optical path control unit 13 that switches paths connected to the n FUTs are connected at an interval T, inject the optical pulse, as a test optical pulse having the pulse width T, sequentially into the paths, then switches the paths at an interval ts that is shorter than the time period T, and emit the reflected light and the back-scattered light from the n FUTs sequentially onto the light reception unit 12 at an interval n×ts; and an arithmetic processing unit 14 that divides the electrical signal output from the light reception unit 12, with an interval equal to the interval ts at which switching the paths is performed, into discrete signals respectively corresponding to the FUTs, and calculates the reflectance distributions of the reflected light and the back-scattered light of the respective FUTs.

公开(公告)号：US20240280403A1

公开(公告)日：2024-08-22

申请号：US18567606

申请日：2021-06-09

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yoshifumi WAKISAKA ,  Daisuke IIDA ,  Yusuke KOSHIKIYA ,  Hiroyuki IIDA ,  Nazuki HONDA

IPC: G01H9/00 ,  G01D5/353

CPC classification number: G01H9/004 ,  G01D5/35358

Abstract: The present disclosure relates to a vibration measuring instrument that repeatedly injects a plurality of light pulses with different optical frequencies into an optical fiber, and performs distributed acoustic sensing-phase (DAS-P). In the vibration measuring instrument, light pulses having a waveform with a spectral side lobe smaller than a side lobe of a rectangular wave are used as the plurality of light pulses.