Fiber bragg grating sensing method and system based on wavelength-division multiplexing multichannel output time-domain address finding technology

Abstract

The invention discloses a fiber bragg grating sensing method and system based on a wavelength-division multiplexing multichannel output time-domain address finding technology. A controlled light source is provided and outputs light wave signals which are scanned by wavelengths. The light wave signals are coupled with a coupler after being subjected to bragg reflection. Finally, the light wave signals are converted to electric pulse train signals and transmitted to a delay control switch array after being amplified, and the electric pulse train signals are distributed and output in sequence among output channels of the delay control switch array through the delay control switch array, so that time-domain address finding is realized. With the help of wavelength scanning and selective conduction of an analogue electronic switch array, a wavelength-division multiplexing signal processing technology is organically combined with the time-domain address finding technology, therefore, a demand of an optical distance interval between adjacent sensing elements in an ordinary time-domain address finding technology is converted into a demand of a wavelength interval, so that the dependence on accessing a delay optical fiber between the adjacent sensing elements is avoided.

Description

technical field [0001] The invention relates to a fiber grating sensor network technology, which realizes quasi-distributed sensing by querying the sensor element address and demodulating the sensing signal. It can be used in the fields of intelligent structure, engineering structure health monitoring and disaster early warning. Background technique [0002] Using some means to make the physical structure of the optical fiber distributed regularly along the axis to change the path of light propagating in it, such a photonic device is called Fiber Bragg grating (FBG). It was first successfully developed by Hill in 1978 in a germanium-doped silica fiber. The common fiber grating is written outside the ultraviolet, and it has a band-stop filtering characteristic for the light wave of the Bragg wavelength, that is, the light wave of the Bragg wavelength returns along the original path due to diffraction (this phenomenon is called Bragg reflection). Other wavelengths pass throu...

AI Technical Summary

Problems solved by technology

[0011] The access of delayed optical fiber is unfavorable to the laying of sensor network and weakens its practicability

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