Method and device for suppressing phase noise of long-distance optical fiber interference system based on optical path difference matching

Abstract

The invention relates to an optical fiber sensing technology and provides a method and device for suppressing phase noise of a long-distance optical fiber interference system based on optical path difference matching so as to solve the problems that the input power of the existing long-distance optical fiber interference system is limited and the phase noise of the existing long-distance optical fiber interference system is increased under the stimulated Brillouin scattering effect. The device comprises a single-frequency laser, an electro-optic phase modulator, a signal source, an erbium-doped optical fiber amplifier, a transmission optical fiber, a matching interferometer, a photoelectric detector and a signal acquisition and processing device. A laser is output by the single-frequency laser and modulated by the electro-optic phase modulator to generate a multi-frequency laser, the multi-frequency laser is amplified by the erbium-doped optical fiber amplifier and input into the matching interferometer by the transmission optical fiber, and a signal is output of the matching interferometer, detected by the photoelectric detector and processed by the signal acquisition and processing device. Suppression on the stimulated Brillouin scattering effect is achieved through the phase modulation technology, the phase noise of the system is reduced through signal frequency phase modulation and interferometer optical path difference matching, and the maximum input power and sensing distance of the system are increased.

Description

technical field [0001] The invention relates to the technical field of optical fiber sensing, in particular to a method and device for suppressing phase noise of a remote optical fiber interference system based on optical path difference matching. Background technique [0002] The optical fiber interference system uses the signal to be measured to modulate the phase of the light transmitted in the optical fiber, and generates an interference signal through an interferometer to detect the signal, which can be applied in the fields of optical fiber communication and optical fiber sensing. Compared with traditional sensing systems, interferometric optical fiber sensing technology based on optical fiber interferometric systems has the advantages of high sensitivity, large dynamic range, and anti-electromagnetic interference. It has been widely used in underwater acoustic signal detection, oil exploration, seismic wave detection and other fields. With the further development of t...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved in the present invention is to propose a method and device for suppressing phase noise of a remote optical fiber interference system with optical path difference matching for the problems of low maximum input power and large phase noise caused by SBS in the existing remote optical fiber interference system

The electro-optical phase modulator is used to generate multi-frequency laser at the input end of the transmission fiber to suppress SBS and the phase noise caused by it, and the modulation signal frequency of the electro-optic phase modulator is designed to match the optical path difference of the interferometer to suppress the multi-frequency laser. phase noise

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