IP Library Granted Patent US 12,529,594
Granted Patent B2
US 12,529,594 · App. 18/275,848 · Granted Jan 20, 2026

Coherent optical measuring device for facility line test

Inventors: Daisuke Iida (Musashino, JP); Yoshitaka Enomoto (Musashino, JP); Chihiro Kito (Musashino, JP); Tatsuya Okamoto (Musashino, JP); Yusuke Koshikiya (Musashino, JP); Yoshifumi Wakisaka (Musashino, JP); Nazuki Honda (Musashino, JP)
Assignee: NTT, Inc.
G01H9/004
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Quick Facts
Patent No.
US 12,529,594
App. No.
18/275,848
Granted
Jan 20, 2026
Kind
B2
Abstract

The present disclosure is an optical line test system that detects a distribution of loss points of an optical line in a longitudinal direction, using a coherent light measurement device, applies vibration to facility disposed on a path of the optical line, detects a vibration point of the optical line in a longitudinal direction upon applying the vibration, using the coherent light measurement device, and identifies the loss point based on correspondence between the detected loss point and vibration point.

Claims (28)

1 . An optical line test system comprising:

detecting a distribution of possible loss points of an optical line in a longitudinal direction, using a coherent light measurement device;

applying vibration to facility disposed on a path of the optical line;

detecting a vibration point of the optical line in a longitudinal direction upon applying the vibration, using the coherent light measurement device;

comparing the vibration point to the distribution of possible loss points; and

identifying the loss point based on correspondence between the vibration point and the distribution of possible loss points.

2 . The optical line test system according to claim 1 , wherein

the coherent light measurement device is an optical time domain reflectometer (OTDR) for performing coherent detection, and the device for

measuring the distribution of possible loss points by time-averaging a plurality of backscattered light waveforms obtained by a plurality of light pulses, and

measuring the vibration point by arranging the plurality of backscattered light waveforms obtained by the plurality of light pulses in accordance with time series.

3 . The optical line test system according to claim 1 , wherein the facility is at least one of a closure, a utility pole, or a manhole.

4 . The optical line test system according claim 1 , wherein

the coherent light measurement device displays the vibration point of the optical line, in the longitudinal direction, on the distribution of possible loss points of the optical line in the longitudinal direction.

5 . The optical line test system according to claim 1 , wherein

the coherent light measurement device transmits at least one of a detection result of the loss point and the vibration point or a result of the identifying to a set terminal.

6 . The optical line test system according to claim 5 , wherein

the coherent light measurement device performs at least one of detection of the distribution of possible loss points of the optical line in a longitudinal direction, and detection of the vibration point of the optical line in the longitudinal direction, in accordance with an instruction from a set terminal.

7 . A coherent light measurement device that is a coherent OTDR for performing coherent detection, the device for

measuring a distribution of possible loss points by time-averaging a plurality of backscattered light waveforms obtained by a plurality of light pulses,

measuring the vibration point by arranging the plurality of backscattered light waveforms obtained by the plurality of light pulses in accordance with time series,

comparing the vibration point to the distribution of possible loss points; and

determining whether the distribution of possible loss points and the vibration point correspond or do not correspond.

8 . An optical line test method comprising:

detecting a distribution of possible loss points of an optical line in a longitudinal direction, using a coherent light measurement device;

applying vibration to facility disposed on a path of the optical line;

detecting a vibration point of the optical line in a longitudinal direction upon applying the vibration, using the coherent light measurement device;

comparing the vibration point to the distribution of possible loss points; and

identifying the loss point based on correspondence between the the vibration point and the distribution of possible loss points.

Assignments (2)
CHANGE OF NAME Recorded Oct 3, 2025
From: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
To: NTT, INC.
Reel/Frame 072995/0203 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 4, 2023
From: IIDA, DAISUKE; ENOMOTO, YOSHITAKA; KITO, CHIHIRO; OKAMOTO, TATSUYA; KOSHIKIYA, YUSUKE; WAKISAKA, YOSHIFUMI; HONDA, NAZUKI
To: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Reel/Frame 064493/0100 →
Continuity (1)
Related Publication 20240118127A1 · Apr 11, 2024
References Cited (14)
US 20210003474A1 · Koshikiya · 2021 [cited by examiner]
US 20210255005A1 · Okamoto · 2021 [cited by examiner]
US 20220155139A1 · Wakisaka · 2022 [cited by examiner]
JP 2017026503A · 2017 [cited by applicant]
JP 2019078637A · 2019 [cited by applicant]
JP 2020052030A · 2020 [cited by applicant]
JP 2020169904A · 2020 [cited by applicant]
WO WO2019172276A1 · 2019 [cited by applicant]
WO 2020026199A1 · 2020 [cited by applicant]
Iida Daisuke et al: “Advances in distributed vibration sensing for optical communication fiber state visualization”, Optical Fiber Technology, vol. 57, Jul. 1, 2020 (Jul. 1, 2020), Amsterdam, NL, pp. 102263, XP093036976… [cited by examiner]
“Overview of Optical Test Module (OTM)”, ANSL R&D Times, No. 33, 2003, https://www.ansl.ntt.co.jp/j/times/033/02/02.html with English captions. [cited by applicant]
“Immersion Detection Technology”, ANSL R&D Times, No. 58, 2009, https://www.ansl.ntt.co.jp/j/times/058/01/01.html with English captions. [cited by applicant]
Daisuke Etal: “Advances in distributed vibration sensing for optical communication fiber state visualization”, Apr. 28, 2020. [cited by applicant]
Merlo Sabina Etal: ““Runways ground monitoring system by phase-sensitive optical-fiber OTDR””, 2017. [cited by applicant]