System capable of synchronously measuring transverse pressure and temperature of fiber grating based on polarization measurement

Abstract

The invention discloses a fiber grating sensing system capable of simultaneously measuring transverse pressure and temperature based on polarization measurement, and belongs to the field of optical fiber sensing. The fiber grating sensing system mainly comprises a tunable laser with high stability, an optical isolator, an optical circulator, a Bragg fiber grating, a polarization-dependent loss tester and a spectrum analyzer. When the fiber grating is subject to the simultaneous action of transverse pressure and temperature, the polarization-dependent loss property of the transmission end obviously changes due to the dual-deflection effect, and the size of the transverse pressure can be demodulated through the measurement of the polarization-dependent loss tester. The reflective light of the fiber grating is inputted to the spectrum analyzer through the optical circulator, and the temperature is measured by analyzing the movement of the center wavelength of the reflective light spectrum. The fiber grating sensing system has the advantages that the dual parameters of the transverse pressure and the temperature can be simultaneously measured, the sensitivity is high, the structure is simple, and the full-light sensing is realized.

Description

technical field [0001] The invention relates to a fiber grating sensor system based on polarization measurement that can simultaneously realize the functions of lateral pressure and temperature measurement, and belongs to the field of fiber sensor. Background technique [0002] In recent years, fiber Bragg gratings (FBGs) have received more and more attention in the field of sensing. The basic working principle of the FBG sensor is that when the FBG is affected by temperature and strain, the drift of its central wavelength changes linearly, and the information of physical parameters such as temperature and strain can be restored by detecting the movement of the wavelength. Compared with traditional electrical sensors, FBG sensors have the following technical advantages: 1. It is not subject to electromagnetic wave interference and has strong corrosion resistance. In view of its wavelength absolute encoding characteristics, it will not be affected by light source fluctuation...

AI Technical Summary

Problems solved by technology

However, this method is limited by the stability of polymer materials and special material structures. Its long-term work stability and repeatability are relatively poor, and it increases the size and load of FBG, and it is also difficult to use it stably for a long time.

[0006] In addition, there is an important technical problem in these two typical technical solutions, that is, there is a serious cross-sensitivity between lateral pressure and temperature, that is, the temperature change of the FBG will greatly affect the accuracy of pressure measurement

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