Title:
FULL-POLARIZATION FARADAY MAGNETIC FIELD SENSOR BASED ON SAGNAC INTERFERENCE SYSTEM, AND MODULATION METHOD
Document Type and Number:
WIPO Patent Application WO/2021/184839
Kind Code:
A1
Abstract:
A full-polarization Faraday magnetic field sensor based on a Sagnac interference system, and a modulation method. The full-polarization Faraday magnetic field sensor comprises a light source (1), an optical fiber coupler (2), a polarizer (3), a polarization beam splitter (4), polarization controllers (5, 9), a magnetic field sensing unit (7), a detector (10), and polarization-maintaining optical fiber rings (6, 8). An optical signal is emitted by the light source (1), passes through the optical fiber coupler (2) and the polarizer (3) in sequence, and is divided into a clockwise path and an anticlockwise path by the polarization beam splitter (4). The polarization controllers (5, 9) and the polarization-maintaining optical fiber rings (6, 8) respectively exist in the two optical paths. Included angles between the fast axis directions of the two polarization-maintaining optical fiber rings (6, 8) and the polarization direction of the polarizer (3) are respectively clockwise 45° and anticlockwise 45°. The two polarization-maintaining optical fiber rings (6, 8) are opposite in winding direction and are equal in diameter and number of turns, so as to counteract errors caused by a Sagnac effect. The magnetic field sensing unit (7) is mainly composed of coupling lenses (11, 15), magnetic flux concentrators (12, 14), and a magneto-optical crystal (13), an external magnetic field affects the polarization state of the optical signal, and measurement of the magnetic field can be implemented by detecting a polarization interference result of an output optical signal.
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Inventors:
ZHANG DENGWEI (CN)
LIANG CUI (CN)
LIANG CUI (CN)
Application Number:
PCT/CN2020/134181
Publication Date:
September 23, 2021
Filing Date:
December 07, 2020
Export Citation:
Assignee:
UNIV ZHEJIANG (CN)
International Classes:
G01R33/032; G01D5/353
Foreign References:
| CN111366881A | 2020-07-03 | |||
| CN103344925A | 2013-10-09 | |||
| CN107515378A | 2017-12-26 | |||
| CN102023287A | 2011-04-20 | |||
| CN109556595A | 2019-04-02 | |||
| KR20190139071A | 2019-12-17 |
Attorney, Agent or Firm:
HANGZHOU QIUSHI PATENT OFFICE CO., LTD. (CN)
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