Sensing demodulation method based on linear array ingaas scanning fbg reflection spectrum

Abstract

The invention provides a FBG (Fiber Bragg Grating) reflectance spectrum sensing demodulation method based on linear array InGaAs scanning, comprising the steps of: a) transmitting optical signals emitted by a wide spectrum light source to a FBG through an optical fiber coupler; b) after the optical signals are reflected by the FBG, transmitting reflectance spectrum optical signals with demodulating information to a linear array InGaAs photoelectric detector; c) the reflectance spectrum optical signals are processed by the linear array InGaAs photoelectric detector to obtain reflectance spectrum light intensity information respectively corresponding to pixel positions in the linear array InGaAs photoelectric detector; d) dividing reflectance spectrum optical signals into a plurality of segments through setting reflectance spectrum light intensity thresholds; e) performing gaussian function fitting analysis on pixel positions and light intensity data corresponding to each segment of reflectance spectra, determining an optimal fitting parameter through a least square method, and obtaining a pixel position corresponding to a light intensity peak value; and f) bring the pixel position corresponding to the light intensity peak value to a corresponding relation between pixel positions and wave lengths to obtain the center wave length value of the segment of reflectance spectra.

Description

technical field [0001] The invention relates to a sensing demodulation method of FBG reflection spectrum, in particular to a sensing demodulation method based on linear array InGaAs scanning FBG reflection spectrum. Background technique [0002] Fiber Bragg Grating (FBG) sensor is a new type of sensing technology that uses light as the carrier and optical fiber as the medium to perceive and transmit external signals. Compared with traditional electrical sensors such as resistance strain gauges, FBG sensors have many advantages such as high sensitivity, strong anti-electromagnetic interference, good explosion-proof performance, strong corrosion resistance, and small size. and other fields have been widely used. [0003] In the fiber grating sensing system, the demodulation technology of reflection spectrum has always been a research difficulty, which affects the accuracy and demodulation speed of the whole testing process. Aiming at the fiber grating sensing system, many de...

AI Technical Summary

Problems solved by technology

The demodulation system based on the linear array detector scanning FBG has no mechanical moving parts and has good stability. However, due to the size limitation of the linear array photodetector, the number of spectral data points is small, and the requirements for the peak-finding positioning algorithm are high.

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