Wave length demodulating system and method based on F-P etalon and reference gratings

Abstract

The invention discloses a wave length demodulating system based on an F-P etalon and reference gratings. According to optical path connection, a broadband light source passes through an isolator and is connected with a tunable F-P filter, light out of the tunable F-P filter enters a coupler and is evenly divided into two paths, and one path enters the F-P etalon, and then enters a first photoelectric detector; the other path is output to a first reference fiber bragg grating, a second reference fiber bragg grating and a sensing fiber bragg grating through an optical circulator, the first reference fiber bragg grating, the second reference fiber bragg grating and the sensing fiber bragg grating are connected in series, reflected light of the fiber bragg gratings passes through the optical circulator and enters a second photoelectric detector, and finally two paths of data are synchronously sampled through a PC. According to a wave length demodulating method based on the F-P etalon and the reference gratings, the tunable F-P filter is controlled by the PC; synchronous data collection is carried out on spectrums of two channels; peak searching calculation is carried out on data collected from the two channels; the sensing optical grating is obtained through calculation. The wave length of the sensing optical grating can be demodulated fast and accurately through the F-P etalon and the reference gratings.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensing, and specifically relates to a wavelength demodulation system based on an F-P etalon and a reference grating, and also relates to a wavelength demodulation method based on an F-P etalon and a reference grating. Background technique [0002] The fiber grating sensor has the characteristics of anti-electromagnetic interference, corrosion resistance, electrical insulation, high sensitivity and low cost. In addition, its wavelength coding characteristics and the advantages of quasi-distributed measurement on a single optical fiber are unmatched by other sensors. application prospects. The FBG sensor is a wavelength-modulating device. The change of the external physical quantity will affect the central wavelength of the FBG. By measuring the change of the central wavelength of the FBG, the change of the external physical quantity can be obtained. But at present, one of the main obstacles...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a wavelength demodulation system based on F-P etalon and reference grating, which solves the problem of low detection accuracy of the sensor grating to be measured in the demodulation system existing in the prior art

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