Polarization-maintaining fiber grating two-dimensional vector vibration sensor

Abstract

The invention discloses a polarization-maintaining fiber grating two-dimensional vector vibration sensor. The sensor comprises a broadband light source, a polarization control unit, a sensing probe and an orthogonal polarization demodulation unit, wherein the polarization control unit comprises a polarizer and a polarization controller, the sensing probe comprises an optical fiber probe, the optical fiber probe comprises a polarization-maintaining fiber grating and a cladding-fiber core energy re-coupling structure and is used for sensing the environment vibration information, the optical fiber probe is written in polarization-maintaining fiber, the cladding-fiber core energy re-coupling structure is welded through a polarization-maintaining / single-mode fiber core axial aligning mode, the orthogonal polarization demodulation unit comprises a filter, a polarization beam splitter, two photoelectric detectors and an orthogonal polarization vector synthesizer, and the polarization control unit, the sensing probe and the orthogonal polarization demodulation unit are connected through an optical fiber circulator or a coupler. By the aid of the mechanism, the two-dimensional vibration direction identification based on the single-optical fiber grating can be achieved. The mechanism has the advantages of being high in flexibility, compact in structure, low in cost and easy for network deployment.

Description

technical field [0001] The invention relates to the field of vibration sensor design, in particular to an orthogonally polarized fiber grating two-dimensional vector vibration sensor capable of identifying vibration directions. Background technique [0002] Vibration sensors are widely used in the fields of building structural health detection, earthquake disaster prevention, oil and gas exploration, and national defense security monitoring. Timely diagnosis of its health status; by recording the source of the earthquake, studying the internal structure of the earth and the propagation characteristics of seismic waves, the impending earthquake prediction can be realized; by detecting the elastic waves caused by the reflection or refraction of the artificial vibration through the rock interface, the underground geological structure can be understood to find oil and gas traps to realize oil and gas storage exploration; by detecting ground waves caused by intrusion targets, tar...

AI Technical Summary

Problems solved by technology

This type of electronic vibration sensor can be divided into moving coil type, eddy current type, piezoelectric type, piezoresistive type, etc. in terms of working principle, but the following problems generally exist: it is susceptible to electromagnetic interference, especially electronic devices are prone to sparks, and in There are safety hazards in the application in the field of oil and gas exploration

[0010] Therefore, the miniaturized and networkable sensing technology that can identify the multi-dimensional vibration direction based on the polarization-maintaining fiber grating sensing unit has not been reported yet, and this kind of high-sensitivity fiber-optic two-dimensional vector Vibration sensors have become an urgent need for the development of modern sensing technology and industrial applications

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