公开(公告)号：US20230088679A1

公开(公告)日：2023-03-23

申请号：US17798535

申请日：2020-02-13

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Kazutaka NOTO ,  Nazuki HONDA ,  Hiroyuki OSHIDA

IPC: G01D5/353 ,  G01L1/24 ,  G01K11/322 ,  G01H9/00

Abstract: An object of the present disclosure is to detect a microbend in an optical fiber before the light-receiving intensity of a transmission device decreases. The present disclosure relates to a device configured to measure guided acoustic wave Brillouin scattering in a measurement target optical fiber, and detect a microbend in the measurement target optical fiber based on a characteristic around a peak of the guided acoustic wave Brillouin scattering.

公开(公告)号：US20230085614A1

公开(公告)日：2023-03-16

申请号：US17798299

申请日：2020-02-13

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Kazutaka NOTO ,  Nazuki HONDA ,  Hiroyuki OSHIDA

IPC: G01N25/68 ,  G01K11/322

Abstract: An object of the present disclosure is to realize water immersion detection that does not require a replacement module, and does not cause any optical loss. The present disclosure relates to a device configured to measure guided acoustic wave Brillouin scattering in a measurement target optical fiber, and detect water immersion of the measurement target optical fiber based on a characteristic around a peak of the guided acoustic wave Brillouin scattering.

公开(公告)号：US20210003474A1

公开(公告)日：2021-01-07

申请号：US16977882

申请日：2019-03-05

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yusuke KOSHIKIYA ,  Atsushi NAKAMURA ,  Kazutaka NOTO ,  Tetsuya MANABE

IPC: G01M11/00

Abstract: An object of the present disclosure is to provide an optical fiber cable monitoring method and an optical fiber cable monitoring system capable of linking information obtained from a measurement result with information stored in a DB and accurately specifying a loss occurrence location on an optical fiber cable. The optical fiber cable monitoring method according to the present disclosure uses two types of optical fiber measurement techniques having different sensitivities. Each of closure locations on the optical fiber cable is acquired with a high-sensitivity measurement technique, and geographical location information and the closure locations on the optical fiber are linked in an arrangement order of the closures. Thus, an operator can recognize an actual location (geographical location information) of a closure that is linked to a location of a point of abnormality on the optical fiber cable when an abnormality in the closure is detected with a low-sensitivity measurement technique.

公开(公告)号：US20250018518A1

公开(公告)日：2025-01-16

申请号：US18711957

申请日：2021-12-01

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takui UEMATSU ,  Kazutaka NOTO ,  Hiroyuki IIDA ,  Hidenobu HIROTA ,  Kazunori KATAYAMA

IPC: B24B13/00 ,  C03C25/005

Abstract: An object of the present disclosure is to provide an optical multiplexing/demultiplexing circuit manufacturing device and an optical multiplexing/demultiplexing circuit manufacturing method for polishing a portion of a side surface of an optical fiber core wire by a desired polishing amount without measuring optical loss by cutting an active optical fiber core wire.
To achieve the object described above, the optical multiplexing/demultiplexing circuit manufacturing device according to the present disclosure includes: an optical fiber core wire holding unit having a groove in which a portion of a side surface of an optical fiber core wire is embedded so as to protrude from an open plane by a predetermined distance; a polishing unit in which a polishing flat surface facing the open plane in parallel polishes the portion of the side surface of the optical fiber core wire; and a control unit that causes the polishing unit to start polishing the portion of the side surface of the optical fiber core wire and to finish polishing when the polishing flat surface of the polishing unit reaches the open plane.

公开(公告)号：US20240031019A1

公开(公告)日：2024-01-25

申请号：US18028907

申请日：2020-10-14

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Hidenobu HIROTA ,  Takui UEMATSU ,  Hiroyuki IIDA ,  Kazutaka NOTO ,  Kenji INOUE

IPC: H04B10/07 ,  H04B10/25 ,  H04B10/272

CPC classification number: H04B10/07 ,  H04B10/25 ,  H04B10/272

Abstract: An object of the present invention is to provide a monitoring device and an optical fiber identification method capable of efficiently identifying an optical fiber at a construction site.
The monitoring device 71 includes a light receiver 74 that receives an optical signal SL leaked from an optical fiber, a counter 75 that counts the number of unique numbers indicating transmission sources included in the optical signal SL, and a display unit 76 that displays the number of unique numbers. The monitoring device 71 further includes a control unit 77 that causes the display unit 76 to display that a portion where the optical signal SL has leaked is between the 8-branch splitter 51 and the OLT 11 when the number of unique numbers is two or more, and that causes the display unit 76 to display that it is unknown whether a portion where the optical signal SL has leaked is between the 8-branch splitter 51 and the OLT 11 or between the 8-branch splitter 51 and the ONU 21 when the number of unique numbers is one.

公开(公告)号：US20230221153A1

公开(公告)日：2023-07-13

申请号：US17928264

申请日：2020-06-03

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Kazutaka NOTO ,  Nazuki HONDA ,  Hiroyuki OSHIDA

IPC: G01D21/02 ,  G01M11/02

CPC classification number: G01D21/02 ,  G01M11/02 ,  G01M11/3109

Abstract: The present disclosure is directed to enabling detection of microbending even in a case where a microbending loss varies.
The present disclosure relates to a device that measures a transmission loss in a measured optical fiber to be targeted, and detects microbending in the measured optical fiber based on periodicity of the transmission loss.

公开(公告)号：US20220299401A1

公开(公告)日：2022-09-22

申请号：US17636093

申请日：2019-08-23

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Nazuki HONDA ,  Kazutaka NOTO ,  Hiroyuki OSHIDA

IPC: G01M11/02 ,  H04B10/071

Abstract: An object of the present invention is to provide an optical fiber test method, an optical fiber test apparatus, and a program, capable of detecting a boundary of an optical fiber line facility regardless of a change in a noise amount. A change amount (a differential value) of an OTDR waveform increases toward a distal end due to noise effects, making it difficult to determine a boundary of the optical fiber using the change amount. Therefore, in the present invention, a dispersion of the OTDR waveform, which increases toward a distal end due to noise effects, is also used to determine the boundary of the optical fiber. In other words, in the present invention, the noise amount is expressed by the dispersion, and the dispersion is compared with the change amount such as a differential value as a threshold, to determine the boundary of the optical fiber. For this reason, when noise increases, the threshold increases together with an increase in the change amount, and therefore, the boundary of the optical fiber can be determined regardless of noise.