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 grating sensing method and system based on wavelength division multiplexing multi-channel output time-domain address query technology, a controlled light source is set, and a wavelength-scanned light wave signal is output through the controlled light source, and the light wave signal is reflected by Bragg After processing, it is coupled by a coupler, and finally the detector converts it into an electric pulse train signal and transmits it to the delay control switch array after being amplified. Each output channel of the array is distributed sequentially to realize address query in time domain. The present invention realizes the organic combination of wavelength division multiplexing signal processing technology and time-domain address query technology by means of wavelength scanning and selective conduction of analog electronic switch arrays, and the ordinary time-domain address query technology is used to determine the optical distance between adjacent sensing elements. The interval requirement is transformed into the wavelength interval requirement, thereby putting aside the dependence on the access delay fiber between adjacent sensing elements.

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

Images