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公开(公告)号：US20220120635A1
公开(公告)日：2022-04-21
申请号：US17426631
申请日：2019-09-04
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Atsushi NAKAMURA , Nazuki HONDA , Daisuke IIDA , Hiroyuki OSHIDA , Keiji OKAMOTO
Abstract: An object of the present invention is to provide an optical pulse test apparatus and an optical pulse test method that are capable of determining a change in state of an optical fiber connection portion without the need for reference and without being affected by changes in gap interval before and after the change in state. The optical pulse test apparatus according to the present invention is configured to perform an OTDR measurement by using test optical pulses having spectral widths of from several nm to several hundred nm arranged at intervals of several ten nm to several hundred nm, calculate a reflection peak value caused by the Fresnel reflection at the connection portion from the obtained OTDR waveform, and determine a state such as water immersion of the optical fiber connection portion based on the value.
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22.发明申请公开(公告)号：US20220107218A1
公开(公告)日：2022-04-07
申请号：US17429861
申请日：2020-01-29
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Tatsuya OKAMOTO , Daisuke IIDA , Hiroyuki OSHIDA
Abstract: It is an object of the present invention to provide an aerial optical fiber cable inspection method, an aerial optical fiber cable inspection device, and a program which can identify a cable sagging section from vibration sensing results. In the aerial optical fiber cable inspection method according to the present invention, a vibration distribution waveform along the longitudinal direction of an aerial optical fiber cable measured using an optical fiber vibration sensing device is received as an input, a standard deviation of the amplitude of vibration at each position in the vibration distribution waveform is calculated, and a section with a standard deviation larger than that of other sections is identified as a cable sagging section.
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公开(公告)号：US20220065744A1
公开(公告)日：2022-03-03
申请号：US17413880
申请日：2019-12-03
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Atsushi NAKAMURA , Keiji OKAMOTO , Hiroyuki OSHIDA
IPC: G01M11/00
Abstract: An object is to provide an optical pulse test method and an optical pulse test device with which it is possible to measure transmission losses of a basic mode and a first higher-order mode at a connection point at which two-mode optical fibers are connected in series, without switching the mode of input test light.
An optical pulse test device according to the present invention inputs a test optical pulse in a basic mode (or a first higher-order mode) from one end of an optical fiber under test, the test optical pulse having such a wavelength that the test optical pulse can propagate in the basic mode and the first higher-order mode, measures intensity distributions of a basic mode component and a first higher-order mode component of return light of the test optical pulse relative to the distance from the one end, finds, from the intensity distributions, losses of the basic mode component and the first higher-order mode component of the return light at a desired connection point of the optical fiber under test, and calculates transmission losses of the basic mode and the first higher-order mode at the connection point based on expressions (8) (or expressions (9)).-
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
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：US20230236005A1
公开(公告)日：2023-07-27
申请号：US17918950
申请日：2020-04-22
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Masaki NAKAMORI , Yukihiro GOTO , Hiroyuki OSHIDA
IPC: G01B11/06 , G01N21/3581 , G01N21/3563
CPC classification number: G01B11/06 , G01N21/3581 , G01N21/3563
Abstract: An object permittivity measurement apparatus according to the present disclosure includes: a light wave distance measurement device configured to measure reciprocating time t of a light wave with which an object is irradiated and that is reflected and returned from the object, and calculate a distance L to the object using the following equation (1),
L=ct/2 (1)
c: light speed;
an electromagnetic wave phase measurement device configured to measure a rotated phase φ of an electromagnetic wave having a frequency f with which the object is irradiated and that is reflected and returned from the object; and
a permittivity calculation circuit configured to calculate permittivity ε of a foreign material on an object surface using the following equation (2),
φ=4πLf/c+4π(ε)1/2df/c (2)
d: a thickness of the foreign material on the object surface.-
Patent Agency Ranking
公开(公告)号：US20230152170A1
公开(公告)日：2023-05-18
申请号：US17798172
申请日：2020-03-05
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Atsushi NAKAMURA , Daisuke IIDA , Hiroyuki OSHIDA , Tatsuya OKAMOTO , Tomokazu ODA , Yoshifumi WAKISAKA
CPC classification number: G01L1/242 , G01L5/0042
Abstract: An object of the present disclosure is to provide a method and an apparatus for acquiring curvature and torsion using an inexpensive sensor medium. Disclosed is a measurement apparatus including a fiber ribbon including a plurality of coated fibers arranged in parallel, a strain measurement unit that measures strain amounts of the plurality of coated fibers, and an arithmetic processing unit that calculates curvature and torsion of the fiber ribbon using a strain amount of a coated fiber arranged in a middle portion of the plurality of coated fibers and a strain amount of a coated fiber arranged in a marginal portion of the plurality of coated fibers.
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公开(公告)号：US20230144218A1
公开(公告)日：2023-05-11
申请号：US17926655
申请日：2020-06-03
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Tomokazu ODA , Hiroyuki OSHIDA , Daisuke IIDA , Atsushi NAKAMURA , Yuto SAGAE
IPC: G01M11/00
CPC classification number: G01M11/39
Abstract: The present invention has an object to provide an optical fiber testing method and an optical fiber testing device capable of measuring the delay ratio between the modes at each position of a fiber over a long distance in which a plurality of modes propagate.
An optical fiber testing method and its device according to the present invention, measure the change amount for the wave number k of a Brillouin Frequency Shift ν in stimulated Brillouin scattering generated in the same acoustic mode, with respect to each target propagation mode. Thereby, the ratio of the change amount measured at each propagation mode is acquired as the group delay ratio between the modes.-
公开(公告)号：US20220244137A1
公开(公告)日：2022-08-04
申请号：US17596368
申请日：2019-06-11
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Atsushi NAKAMURA , Keiji OKAMOTO , Hiroyuki OSHIDA
IPC: G01M11/00
Abstract: The purpose of this invention is to provide an optical pulse testing method and optical pulse testing device capable of measuring the loss at an end farther than an axially misaligned connection point at which inter-mode crosstalk occurs independently from the crosstalk value at the point. In this optical pulse testing method, a matrix (loss and crosstalk) representing the mode coupling at a near-end connection point is calculated, and an OTDR waveform having the effects of crosstalk eliminated therefrom is obtained by numerical processing using the calculated matrix representing the mode coupling.
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29.发明申请公开(公告)号：US20220230347A1
公开(公告)日：2022-07-21
申请号：US17608975
申请日：2019-05-08
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Hitoshi NIIGAKI , Masaki WAKI , Masaaki INOUE , Yasuhiro YAO , Tomoya SHIMIZU , Hiroyuki OSHIDA , Kana KURATA , Shingo ANDO , Atsushi SAGATA
Abstract: It is possible to estimate a slack level accurately in consideration of a shape of a deformed cable. A point cloud analysis device sets a plurality of regions of interest obtained by window-searching a wire model including a quadratic curve model representing a cable obtained from a point cloud consisting of three-dimensional points on an object, the region of interest being divided into a first region and a second region. The point cloud analysis device compares information on the first region with information on the second region based on the point cloud included in the region of interest and the quadratic curve model for each of the plurality of regions of interest, calculates a degree of division boundary representing a degree to which a division position between the first region and the second region of the plurality of regions of interest is a branch point of the cable, and detects a division boundary point that is a branch point of a cable represented by the quadratic curve model based on the degree of division boundary calculated for each of the plurality of regions of interest.
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公开(公告)号：US20220149934A1
公开(公告)日：2022-05-12
申请号：US17430016
申请日：2020-01-29
Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Tatsuya OKAMOTO , Daisuke IIDA , Hiroyuki OSHIDA
IPC: H04B10/071 , H04B10/2507
Abstract: The purpose of the present invention is to provide a device for optical frequency domain reflectometry and a method thereof that can measure a reflectance distribution with less spatial resolution degradation due to a phase noise, without using a wideband receiving system even when a long-distance measurement is performed. The device for optical frequency domain reflectometry according to the present invention is provided with a delay optical fiber for delaying a local light by a prescribed time, and obtains information on a relative delay of a backscattered light from an optical fiber under measurement with respect to the local light and information on the positivity and the negativity of a beat frequency by measuring an in-phase component and a quadrature component of a beat signal obtained by multiplexing the backscattered light from the optical fiber under measurement and the local light delayed by the delay optical fiber, so as to obtain a reflectance distribution in a longitudinal direction of the optical fiber under measurement based on these pieces of information.
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