Orthogonal polarization fiber bragg grating vector torsion sensing device and detection method thereof

Abstract

The invention discloses an orthogonal polarization fiber bragg grating vector torsion sensing device and a detection method thereof. The torsion sensing device comprises a vertical cavity surface emitting laser (VCSEL) light source, a polarization processing unit, a sensing probe, a orthogonal polarization demodulation processing unit and an optical fiber circulator / coupler, and the polarization processing unit, the sensing probe and the orthogonal polarization demodulation processing unit are connected through the optical fiber circulator / coupler. The detection method of the torsion sensing device includes that a polarization maintaining optical fiber bragg grating is used as a sensing unit, two groups of mutually orthogonal polarization state energy intensity messages are simultaneously obtained through an orthogonal polarization vector demodulation unit, and accurate measurement of torsion angles and directions can be achieved through a vector analysis module. The torsion sensing device uses a full optical fiber structure so that the torsion sensing device has the advantages of being high in integration level, good in stability, compact in structure, high in sensitivity, low in costs, easy to network and capable of achieving functions of temperature changing self-calibration and light source shaking inhibiting.

Description

technical field [0001] The invention relates to a torsion sensing device and a detection method thereof, in particular to an orthogonally polarized fiber grating vector torsion sensing device and a detection method thereof, belonging to the field of torsion sensors. Background technique [0002] Due to the increasing demand for engineering instruments and instrument testing, the research and development of torsion sensors has been paid more and more attention and developed rapidly. As far as the sensing structure is concerned, the reported torsion sensors can be divided into mechanical, electromagnetic, volume grating and optical fiber structures. The mechanical sensing structure is based on the axial strain gauge sensing, which requires high machining and high cost; the electromagnetic sensing structure is based on the electromagnetic clutch type dynamometer, which is large in size and susceptible to electromagnetic field interference; the volume grating type Sensors are l...

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Problems solved by technology

This kind of sensor also has high sensitivity, but its disadvantage is that it needs to use spatial geometrical optics for polarization analysis, non-full fiber demodulation, large volume and poor stability of the sensing system; at the same time, the sensing system can only obtain a single The energy output in the polarization state (obtained by the polarization analysis of the spatial geometric optics device) cannot simultaneously obtain two sets of mutually orthogonal polarization state energy information, so the vector torsion detection cannot be realized

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