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公开(公告)号：US09933581B2
公开(公告)日：2018-04-03
申请号：US15300494
申请日：2015-03-31
Applicant: FUJIKURA LTD. , NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Inventor： Takaharu Matsuda , Hung Huu Luong , Tatsuya Ota , Kazuhiro Takizawa , Hiroichi Katayose , Koji Ishizuka , Makoto Shinpo , Kunihiro Toge
CPC classification number: G02B6/382 , G02B6/3806 , G02B6/3821 , G02B6/3846 , G02B6/3881 , G02B6/443 , G02B6/4471
Abstract: An optical fiber splicer includes a fiber fixing portion, a first optical fiber fixed to the fiber fixing portion, a clamp portion which is capable of holding and fixing an extending portion extended from the fiber fixing portion of the first optical fiber and a tip portion of a second optical fiber optically connected to the extending portion of the first optical fiber between a base member and a pressing member being openable and closable with respect to the base member, and a solid index matching material which is attached to a tip surface of the extending portion of the first optical fiber and is interposed between the first optical fiber and the second optical fiber.
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2.发明授权公开(公告)号：US11378489B2
公开(公告)日：2022-07-05
申请号：US16975821
申请日：2019-02-26
Applicant: Nippon Telegraph and Telephone Corporation
Inventor： Hiroshi Takahashi , Tomokazu Oda , Kunihiro Toge , Tetsuya Manabe
IPC: G01M11/02 , G01M11/00 , H04B10/2581
Abstract: An object is to provide a propagation property analyzing apparatus that can alleviate the influence of an error caused by crosstalk, and accurately evaluate a few-mode optical fiber that multiplexes a plurality of modes, in a distributional and non-destructive manner. Provided is a propagation property analyzing apparatus that analyzes propagation properties of a few-mode optical fiber that multiplexes a plurality of modes, which is an optical fiber under test, in a lengthwise direction thereof, through Brillouin time domain analysis, the propagation property analyzing apparatus including: means for inputting probe light in a desired mode from a distal end of the optical fiber under test; means for inputting a light pulse that is in the desired mode and that has a frequency difference equivalent to a Brillouin frequency shift in the desired mode, relative to the probe light, from a proximal end of the optical fiber under test, as pump light corresponding to the probe light; and means for inputting a light pulse that is in another mode different from the desired mode and that has a frequency difference equivalent to a Brillouin frequency shift in the other mode, relative to the probe light, as secondary probe light corresponding to the probe light, from the proximal end of the optical fiber under test.
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公开(公告)号：US20210310897A1
公开(公告)日：2021-10-07
申请号：US17269151
申请日：2019-08-14
Applicant: Nippon Telegraph and Telephone Corporation
Inventor： Tomokazu Oda , Hiroshi Takahashi , Kunihiro Toge , Tetsuya Manabe
Abstract: An optical fiber loss measurement device includes a unit configured to input pump light at a first frequency in a predetermined mode to a measurement target optical fiber in which a plurality of modes propagate from a first end, and input probe light at a second frequency to which a Brillouin frequency shift is applied to a second end, a Brillouin gain acquisition unit configured to measure an intensity of light output from the first end to acquire Brillouin gains in a longitudinal direction of the measurement target optical fiber using a BOTDA method, and a unit configured to measure a loss in the predetermined mode of the measurement target optical fiber, and the probe light is in a mode in which an electric field distribution in a cross section of the measurement target optical fiber is axisymmetric.
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4.发明授权公开(公告)号：US11385082B2
公开(公告)日：2022-07-12
申请号：US17042638
申请日：2019-03-26
Applicant: Nippon Telegraph and Telephone Corporation
Inventor： Hiroshi Takahashi , Kunihiro Toge , Tomokazu Oda , Tetsuya Manabe
IPC: G01D5/353
Abstract: An environmental property measurement apparatus includes a unit configured to receive probe light in a desired mode from one end of a measurement optical fiber, a unit configured to receive, from the other end of the measurement optical fiber, a light pulse in the desired mode as a pump light pulse with respect to the probe light, the light pulse having a frequency difference corresponding to a Brillouin frequency shift of the measurement optical fiber relative to the probe light on a high frequency side, and a unit configured to receive second probe light having the frequency difference corresponding to the Brillouin frequency shift of the measurement optical fiber relative to the probe light on a low frequency side from the other end of the measurement optical fiber, the second probe light being probe light with respect to the probe light in another mode different from the desired mode.
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公开(公告)号：US11300455B2
公开(公告)日：2022-04-12
申请号：US16982678
申请日：2019-03-26
Applicant: Nippon Telegraph and Telephone Corporation
Inventor： Shingo Ono , Kunihiro Toge , Tetsuya Manabe
Abstract: Provided is an optical spectrum line width calculation method, apparatus, and program capable of calculating a spectrum line width of a laser to be measured from an optical interference signal generated by an optical interferometer having a delay line, based on a phase of the optical interference signal having a delay time longer than a delay time due to the delay line. The optical spectrum line width measurement apparatus includes a Mach-Zehnder interferometer, an optical receiver that receives an optical interference signal emitted from the Mach-Zehnder interferometer, an A/D converter that converts an analog electric signal output from the optical receiver into a digital electric signal, and a processing apparatus that processes the digital electric signal. Two light beams having a delay difference τ are generated from light emitted from the laser to be measured, and an optical interference signal is generated by multiplexing the two light beams.
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Patent Agency Ranking
公开(公告)号：US20210278272A1
公开(公告)日：2021-09-09
申请号：US17256532
申请日：2019-06-19
Applicant: Nippon Telegraph and Telephone Corporation
Inventor： Kunihiro Toge , Daisuke Iida , Shingo Ono , Yoshifumi Wakisaka , Tetsuya Manabe
Abstract: A distributed optical fiber vibration measurement device includes a phase constant difference computation unit causing the first backscattered light generated at the points of a plurality of optical fibers under test that are integrated to interfere with another light to obtain two AC components and determining a phase constant difference from the two AC components, a phase distribution data creation unit comparing amplitudes between the two AC components obtained by causing the first backscattered light generated at the points of the optical fibers under test to interfere with the other light and selecting, for each of the points, phase data regarding one of the two AC components having a larger amplitude to create phase distribution data with the phase data, and a vibration measurement unit identifying an optical path length difference between any two points of the optical fiber under test to measure vibration of the optical fiber under test.
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7.发明申请公开(公告)号：US20210018343A1
公开(公告)日：2021-01-21
申请号：US17042638
申请日：2019-03-26
Applicant: Nippon Telegraph and Telephone Corporation
Inventor： Hiroshi Takahashi , Kunihiro Toge , Tomokazu Oda , Tetsuya Manabe
IPC: G01D5/353
Abstract: An environmental property measurement apparatus includes a unit configured to receive probe light in a desired mode from one end of a measurement optical fiber, a unit configured to receive, from the other end of the measurement optical fiber, a light pulse in the desired mode as a pump light pulse with respect to the probe light, the light pulse having a frequency difference corresponding to a Brillouin frequency shift of the measurement optical fiber relative to the probe light on a high frequency side, and a unit configured to receive second probe light having the frequency difference corresponding to the Brillouin frequency shift of the measurement optical fiber relative to the probe light on a low frequency side from the other end of the measurement optical fiber, the second probe light being probe light with respect to the probe light in another mode different from the desired mode.
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公开(公告)号：US11920974B2
公开(公告)日：2024-03-05
申请号：US15734115
申请日：2019-05-23
Applicant: Nippon Telegraph and Telephone Corporation
Inventor： Tatsuya Okamoto , Daisuke Iida , Kunihiro Toge , Tetsuya Manabe
Abstract: A vibration distribution measurement system includes a frequency sweep light source that outputs frequency sweep light, an optical splitter that splits the frequency sweep light into probe light and local light, an optical mixer that mixes backscattered light from the sensing fiber as signal light with the local light, the backscattered light being obtained by causing the probe light to be incident on the sensing fiber, and an analysis unit that analyzes a beat signal obtained from output light of the optical mixer. The analysis unit estimates a distance offset from a measurement result obtained by measuring a distribution waveform of the signal light by measuring the beat signal at a measurement time sufficiently shorter than a cycle of the vibration of the sensing fiber, and measures a distribution of a vibration at any position by compensating for the distance offset.
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公开(公告)号：US11385128B2
公开(公告)日：2022-07-12
申请号：US17266038
申请日：2019-08-01
Applicant: Nippon Telegraph and Telephone Corporation
Inventor： Hiroshi Takahashi , Kunihiro Toge , Tomokazu Oda , Tetsuya Manabe
IPC: G01M11/00
Abstract: An optical test system capable of accurately measuring a loss of each mode at each position of an optical fiber which propagates a plurality of modes is provided. An optical fiber loss measuring apparatus for measuring using an OTDR technique includes a crosstalk suppressing light input unit that inputs light of a different mode different from the predetermined mode, the different mode causing crosstalk to the probe light, to the target optical fiber to be measured through the near end as crosstalk suppressing light at a second frequency obtained by giving a frequency that is equivalent to a Brillouin frequency shift of the predetermined mode to a first frequency, a light separating unit that removes light of the second frequency from light that is output from the target optical fiber to be measured through the near end to separate light of the first frequency, and a propagation mode loss measuring unit that measures an intensity of the separated light to measure a loss of each propagation mode at each position of the target optical fiber to be measured.
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公开(公告)号：US20210215532A1
公开(公告)日：2021-07-15
申请号：US15734115
申请日：2019-05-23
Applicant: Nippon Telegraph and Telephone Corporation
Inventor： Tatsuya Okamoto , Daisuke Iida , Kunihiro Toge , Tetsuya Manabe
Abstract: A vibration distribution measurement system includes a frequency sweep light source that outputs frequency sweep light, an optical splitter that splits the frequency sweep light into probe light and local light, an optical mixer that mixes backscattered light from the sensing fiber as signal light with the local light, the backscattered light being obtained by causing the probe light to be incident on the sensing fiber, and an analysis unit that analyzes a beat signal obtained from output light of the optical mixer. The analysis unit estimates a distance offset from a measurement result obtained by measuring a distribution waveform of the signal light by measuring the beat signal at a measurement time sufficiently shorter than a cycle of the vibration of the sensing fiber, and measures a distribution of a vibration at any position by compensating for the distance offset.
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