A high-sensitivity optical fiber Fabry-Perot stress sensor and its sensing method

Abstract

The invention discloses a high-sensitivity optical fiber Fabry-Perot stress sensor, comprising: a broadband light source, an isolator, a coupler, a polarization controller, a polarization-maintaining optical fiber, a hollow-core optical fiber and a spectrometer; both ends of the hollow-core optical fiber are connected to Single-mode fiber fusion splicing to form a fiber Fabry-Perot interferometer (FPI). One end of the fiber-optic Fabry-Perot interferometer is connected to the polarization controller and then connected to the third port of the coupler. The fiber-optic Fabry-Perot interferometer The other end of the polarization-maintaining fiber is connected to the fourth port of the coupler to form a fiber signac interferometer (FSI); after the broadband light source is connected to the isolator, it is connected to the first port of the coupler, and the spectrometer and coupler Second port connection. The present invention does not need to use expensive processing equipment such as carbon dioxide, has a simple manufacturing process, is easier to popularize, and realizes a significant increase in stress measurement sensitivity.

Description

technical field [0001] The invention relates to the technical field of optical fiber sensing, in particular to a high-sensitivity optical fiber Fabry-Perot stress sensor and a sensing method thereof. Background technique [0002] Due to its small size, stable performance, and strong anti-interference ability, the fiber optic Fabry-Perot interferometer (FPI) stress sensor is widely used in aerospace structure monitoring, building structure health monitoring and other fields. Especially in harsh environments such as high voltage, strong electromagnetic field, flammable and explosive, and high temperature environment, it has good application advantages. The sensitivity performance of the linear fiber optic FPI stress sensor is related to the elasto-optic coefficient of the silica fiber. The elasto-optic coefficient represents the change in the effective refractive index of the fiber caused by the stress disturbance in the fiber. The elastic-optic coefficient of quartz fiber is...

AI Technical Summary

Problems solved by technology

However, this method requires extremely precise manipulation techniques, and the sensitivity achieved is not high

Zhou K et al. proposed an air bubble column type FPI through carbon dioxide laser engraving and an improved arc discharge method. The maximum FPI sensitivity obtained was 56.69pm / με. Although this method obtained a higher sensitivity, it was due to Laser processing equipment such as carbon dioxide is required, the equipment is expensive, and the process is complicated, which is not conducive to popularization

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