Title:
RAYLEIGH INTENSITY PATTERN MEASUREMENT DEVICE AND RAYLEIGH INTENSITY PATTERN MEASUREMENT METHOD
Document Type and Number:
WIPO Patent Application WO/2023/058160
Kind Code:
A1
Abstract:
A Rayleigh intensity pattern measurement device (100) comprises: a broadband wavelength variable LD(1); an optical coupler (4) which causes oscillated LD light to be incident on an optical fiber and emits Rayleigh scattering light from the optical fiber to a path that is different from the incident path of the LD light; a reception unit (13) which receives coherent light and the Rayleigh scattering light from the wavelength variable LD(1); and an RIP digital processing unit (14) which receives an output signal from the reception unit (13) through an AD converter (6), calculates a cross-correlation coefficient from two different Rayleigh intensity pattern signals obtained from the Rayleigh scattering light on the basis of data including phase information, and stores the cross-correlation coefficient obtained from the result of comparison with a given threshold value, wherein when the compared cross-correlation coefficient is smaller than the threshold value, a strain-distribution or a temperature distribution of a subject is measured by calculating the cross-correlation coefficient until the cross-correlation coefficient is equal to or greater than the threshold value and determining a Rayleigh frequency shift from the cross-correlation coefficient that is equal to or greater than the threshold value.
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Inventors:
KISHIDA KINZO (JP)
KOYAMADA YAHEI (JP)
NISHIGUCHI KENICHI (JP)
AZUMA DAIJI (JP)
LI CHE-HSIEN (JP)
KOYAMADA YAHEI (JP)
NISHIGUCHI KENICHI (JP)
AZUMA DAIJI (JP)
LI CHE-HSIEN (JP)
Application Number:
PCT/JP2021/037005
Publication Date:
April 13, 2023
Filing Date:
October 06, 2021
Export Citation:
Assignee:
NEUBREX CO LTD (JP)
International Classes:
G01D5/353
Domestic Patent References:
| WO2010061718A1 | 2010-06-03 | |||
| WO2014083989A1 | 2014-06-05 |
Foreign References:
| JP2009042005A | 2009-02-26 | |||
| JP2011232138A | 2011-11-17 | |||
| US7440087B2 | 2008-10-21 | |||
| US7440087B2 | 2008-10-21 | |||
| JP6552983B2 | 2019-07-31 |
Other References:
Y KOYAMADA: "Novel Technique to Improve Spatial Resolution in Brillouin Optical Time-Domain Reflectometry", IEEE PHOTONICS TECHNOLOGY LETTERS, vol. 19, no. 23, 1 December 2007 (2007-12-01), XP011197164, DOI: 10.1109/LPT.2007.908651
Y. WANG ET AL.: "Distributed Fiber-Optic Dynamic-Strain Sensor With Sub-Meter Spatial Resolution and Single-Shot Measurement", IEEE PHOTONIC JOURNAL, vol. 11, no. 6, December 2019 (2019-12-01), XP011755228, DOI: 10.1109/JPHOT.2019.2946293
J. PASTOR-GRAELLS ET AL.: "Single-shot distributed temperature and strain tracking using direct detection phase-sensitive OTDR with chirped pulses", OPTICS EXPRESS, vol. 24, no. 12, 13 June 2016 (2016-06-13), XP055587402, DOI: 10.1364/OE.24.013121
S. LIEHR ET AL.: "Wavelength-Scanning Distributed Acoustic Sensing for Structual Monitoring and Seismic Application", PROCEEDINGS, vol. 15, 2019, pages 30
D. CHEN ET AL.: "Fiber-optic distributed acoustic sensor based on a chirped pulse and a non-matched filter", OPTICS EXPRESS, vol. 27, no. 20, 30 September 2019 (2019-09-30)
Y. WANG ET AL.: "Distributed Fiber-Optic Dynamic-Strain Sensor With Sub-Meter Spatial Resolution and Single-Shot Measurement", IEEE PHOTONIC JOURNAL, vol. 11, no. 6, December 2019 (2019-12-01), XP011755228, DOI: 10.1109/JPHOT.2019.2946293
J. PASTOR-GRAELLS ET AL.: "Single-shot distributed temperature and strain tracking using direct detection phase-sensitive OTDR with chirped pulses", OPTICS EXPRESS, vol. 24, no. 12, 13 June 2016 (2016-06-13), XP055587402, DOI: 10.1364/OE.24.013121
S. LIEHR ET AL.: "Wavelength-Scanning Distributed Acoustic Sensing for Structual Monitoring and Seismic Application", PROCEEDINGS, vol. 15, 2019, pages 30
D. CHEN ET AL.: "Fiber-optic distributed acoustic sensor based on a chirped pulse and a non-matched filter", OPTICS EXPRESS, vol. 27, no. 20, 30 September 2019 (2019-09-30)
Attorney, Agent or Firm:
PALMO PATENT FIRM, P.C. (JP)
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