Title:
APPARATUS AND METHOD FOR ELIMINATING POLARIZATION FADING IN OFDR
Document Type and Number:
WIPO Patent Application WO/2019/029163
Kind Code:
A1
Abstract:
Provided are an apparatus and method for eliminating polarization fading in OFDR, comprising a linear frequency-swept laser device (1), a polarization-maintaining optical-fiber beamsplitter (2), a main interferometer (3), an auxiliary interferometer (4), a data acquisition card (5), and a computer (6); the main interferometer (3) is used for causing beat frequency interference to occur on frequency-swept laser light entering the main interferometer (3) to generate a first beat frequency signal; the auxiliary interferometer (4) causes beat frequency interference to occur on frequency-swept laser light entering the auxiliary interferometer (4) to generate a second beat frequency signal, said second beat frequency signal being converted and then taken to be an external clock of the high-speed data acquisition card (5); triggered by the external clock, the data acquisition card (5) samples the first beat frequency signal at an equal frequency domain interval. In the apparatus, a polarization-maintaining optical fiber and polarization-maintaining fiber optic device are used in each of the main optical path, main interferometer (3), and optical fiber to be tested, thus in the optical path of the main interferometer (3), the state of polarization of the interference signal is strictly controlled to be slow-axis alignment and fast-axis cut-off, basically eliminating the phenomenon of polarization fading. The stability and accuracy of the apparatus in breakpoint detection, loss measurement, and distributed temperature strain sensing are improved significantly. Also provided is a method for eliminating polarization fading in OFDR.
Inventors:
WANG HUIWEN (CN)
ZHANG XIAOLEI (CN)
WEN YONGQIANG (CN)
ZHANG XIAOLEI (CN)
WEN YONGQIANG (CN)
Application Number:
PCT/CN2018/079404
Publication Date:
February 14, 2019
Filing Date:
March 19, 2018
Export Citation:
Assignee:
WUHAN JUNNO TECH CO LTD (CN)
International Classes:
G01D5/353
Domestic Patent References:
| WO2014072845A1 | 2014-05-15 | |||
| WO2007149230A2 | 2007-12-27 |
Foreign References:
| CN102840909A | 2012-12-26 | |||
| CN101718557A | 2010-06-02 | |||
| CN107576341A | 2018-01-12 | |||
| CN104155619A | 2014-11-19 | |||
| CN102322880A | 2012-01-18 | |||
| CN103090813A | 2013-05-08 | |||
| CN104782063A | 2015-07-15 |
Other References:
WU, Y. ET. AL.: "Interference Fiber-optic sensor eliminating ploarization- Induced fading", CHINESE JOURNAL OF SCIENTIFC INSTRUMENT, vol. 35, no. 4, 30 April 2014 (2014-04-30), pages 890, ISSN: 0254-3087
Attorney, Agent or Firm:
HUBEI WUHAN YONGJIA PATENT AGENCY CO., LTD. (CN)
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