Distributed optical fiber sensing system based on phase generated carrier technology

Abstract

A distributed optical fiber sensing system based on the phase generated carrier technology comprises a narrow-linewidth laser device, a modulator, an optoisolator, an erbium-doped optical fiber amplifier, an optical circulator, a fiber grating, a sensing fiber, a Michelson interferometer, a carrier circuit, a photoelectric detector, a data acquisition card, a signal processor and a pulse generator. The input end of the modulator is connected with the output end of the narrow-linewidth laser device. The input end of the optoisolator is connected with the output end of the modulator. The input end of the erbium-doped optical fiber amplifier is connected with the output end of the optoisolator. A port a of the optical circulator is connected with the output end of the erbium-doped optical fiber amplifier. The fiber grating is connected with a port b of the optical circulator. The output end of the carrier circuit is connected with an electrical interface of the Michelson interferometer. The input end of the photoelectric detector is connected with the output end of the Michelson interferometer. One input end of the data acquisition card is connected with the output end of the photoelectric detector, and the other input end of the data acquisition card is connected with the output end of the carrier circuit. The input end of the signal processor is connected with the output end of the data acquisition card. The input end of the pulse generator is connected with the trigger input end of the data acquisition card, and the output end of the pulse generator is connected with an electrical interface of the modulator.

Description

technical field [0001] The invention relates to the field of distributed optical fiber sensing, in particular to the field of distributed optical fiber sensing for measuring dynamic vibration or acoustic signals. Background technique [0002] Distributed optical fiber sensing technology is an important branch of optical fiber sensing. It can continuously monitor the temperature, strain, vibration and Physical quantities such as sound have good application prospects and occupy a major position in the optical fiber sensing market. [0003] According to the sensing principle, distributed optical fiber sensing technology can be mainly divided into two types based on interference principle and backscattering detection technology. The former uses the M-Z type, Sagnac type and composite structure to obtain relevant location information and external physical information through positioning algorithms and demodulation algorithms. The latter uses changes in polarization, light inten...

AI Technical Summary

Problems solved by technology

[0005] In view of this, the main purpose of the present invention is to provide a distributed optical fiber sensing system based on phase generation carrier technology, which can solve the problem of interference and destructive fading, and can realize large signal phase detection of tens of radians

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