公开(公告)号：US20250003775A1

公开(公告)日：2025-01-02

申请号：US18689685

申请日：2021-09-21

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Shingo ONO

IPC: G01D5/353 ,  G01K11/32

Abstract: According to the present disclosure, there is provided an optical fiber sensing device including: a reference interferometer for producing a predetermined difference in propagation delay time in continuous light; a sensor interferometer including a plurality of Mach-Zehnder interferometers having unilateral optical paths functioning as sensor units; and a signal processing unit for performing signal processing by using a light reception signal I(t) obtained by receiving light transmitting through the sensor interferometer and a reference signal Iref-1(t) obtained by receiving light transmitting through the reference interferometer, in which the signal processing unit calculates a cross-correlation Rj between the light reception signal I(t) and the reference signal Iref-j(t), and detects a change in the j-th sensor unit by using a change in the cross-correlation Rj.

公开(公告)号：US20230288191A1

公开(公告)日：2023-09-14

申请号：US18011563

申请日：2020-06-22

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yoshifumi WAKISAKA ,  Shingo ONO ,  Daisuke IIDA ,  Hiroyuki OSHIDA

IPC: G01B11/16 ,  G01D5/353 ,  G01L1/24

CPC classification number: G01B11/16 ,  G01D5/35361 ,  G01L1/24

Abstract: An object of the present disclosure is to measure, at a high sampling rate, a distribution of a vibration pattern applied to each core after being branched.
A strain change measurement apparatus according to the present disclosure inputs, at a reference time, first chirped pulsed light having a chirp having a frequency changing linearly with time to a measurement target optical fiber branched by a coupler, acquires a signal of first scattered light regarding the first chirped pulsed light, inputs, at each monitoring time, second chirped pulsed light having a chirp obtained by time axial inversion with respect to the first chirped pulsed light to the measurement target optical fiber to acquire a signal of second scattered light regarding the second chirped pulsed light, determines a shift amount allowing for maximization of a correlation between a waveform obtained by inverting the signal of the first scattered light around the time axis and further shifting and a waveform of the signal of the second scattered light, and uses the shift amount to calculate a change in strain amount in the measurement target optical fiber from the reference time to each monitoring time.

公开(公告)号：US20250003831A1

公开(公告)日：2025-01-02

申请号：US18688185

申请日：2021-09-15

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Shingo ONO

IPC: G01M11/00

Abstract: The present disclosure relates to a device, including: a first light source for outputting incident light to a measured optical fiber or optical device; a second light source for outputting local light for being multiplexed with transmitted light through the measured optical fiber or optical device; and a signal processing unit for performing digital signal processing on a light-receiving signal I(t) obtained by multiplexing the transmitted light and the local light, wherein the signal processing unit is configured to calculate an autocorrelation function between the light-receiving signal I(t) and a signal I(t+τ) obtained by shifting the light-receiving signal by a time τ, and to measure a delay time difference between propagation modes in the measured optical fiber or optical device, from a peak position of the autocorrelation function.

公开(公告)号：US20240385078A1

公开(公告)日：2024-11-21

申请号：US18688116

申请日：2021-09-17

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Shingo ONO

IPC: G01M11/00

Abstract: The present disclosure is a light reflection measurement device including: a first light source for outputting first continuous light; a second light source for outputting second continuous light as local light; and a signal processing unit for performing digital signal processing on a light reception signal I (t) obtained by multiplexing reflected light that is obtained by irradiating a measurement target with one branched light of the first continuous light, reference light that is the other branched light of the first continuous light, and the local light, in which the signal processing unit calculates an autocorrelation function between the light reception signal I (t) and a light reception signal I (t+τ) obtained by shifting the light reception signal by time τ, and measures reflection on the measurement target by using a position of a peak of the autocorrelation function.

公开(公告)号：US20240353289A1

公开(公告)日：2024-10-24

申请号：US18685766

申请日：2021-09-17

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Shingo ONO

IPC: G01M11/00 ,  G01M11/02

CPC classification number: G01M11/331 ,  G01M11/0207 ,  G01M11/0264

Abstract: A light intensity distribution pattern measurement device according to the present disclosure includes: a two-dimensional imaging sensor for receiving multiplexed light that is obtained by multiplexing transmitted light obtained by injecting one branched light of first continuous light into an optical fiber under measurement, reference light that is the other branched light of the first continuous light, and local light; and a signal processing unit for performing digital signal processing on a light reception signal I (t) of each pixel obtained by the two-dimensional imaging sensor, in which the signal processing unit measures a light intensity distribution pattern, by calculating a square of an autocorrelation function between the light reception signal I (t) and a light reception signal I (t+τ) obtained by shifting the light reception signal by time τ, for each pixel of the two-dimensional imaging sensor.

公开(公告)号：US20240259099A1

公开(公告)日：2024-08-01

申请号：US18563451

申请日：2021-05-31

Applicant: Nippon Telegraph and Telephone Corporation

Inventor： Taku YAMANE ,  Chihiro KITO ,  Shingo ONO

IPC: H04B10/275

CPC classification number: H04B10/275

Abstract: The present disclosure provides an optical access network and a method for designing the same, in which a plurality of optical cable loops, in which optical cables are connected in a loop shape, are disposed between a communication station building and an optical termination position, and the optical cable loops are connected to each other.

公开(公告)号：US20240063911A1

公开(公告)日：2024-02-22

申请号：US18269885

申请日：2021-01-27

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Shingo ONO ,  Chihiro KITO

IPC: H04B10/275 ,  H04Q11/00

CPC classification number: H04B10/2755 ,  H04Q11/0005 ,  H04Q2011/0041

Abstract: An object of the present invention is to provide an optical access network that has high reliability for supporting information communication services and efficiently responds to difficult-to-predict optical fiber demand.
An optical access network configuration according to the present invention includes an optical fiber cable 11 that is looped to connect a wiring section 25 and an exchange office 10 together (hereinafter, an upper loop), an optical fiber cable 21 that is looped and laid in each wiring section 25 (hereinafter, a lower loop), and an optical fiber switching function unit 31 installed at a connection point 30 between the upper loop 11 and the lower loop 21. The optical fiber switching function unit 31 is a wiring board or an optical switch which can be switched by connector connection. The wiring board or the optical switch may be remotely controllable.

公开(公告)号：US20230417630A1

公开(公告)日：2023-12-28

申请号：US18035769

申请日：2020-11-10

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Shingo ONO ,  Atsushi NAKAMURA

IPC: G01M11/00

CPC classification number: G01M11/3109

Abstract: A backscattered light intensity measurement unit is presented that acquires a combination of backscattered light intensities of individual transmittable spatial channels of an optical fiber obtained when test light, for the respective transmittable spatial channels of the optical fiber, is incident on the optical fiber, and a transfer matrix calculation unit that calculates a transfer matrix for each section of the optical fiber in order from a side closer to an incident end of the test light, in which characteristics in a section of the optical fiber are evaluated by using the transfer matrix.