Fully-distributed optical fiber sensor in combination of optical fiber Raman frequency shifter and Raman amplifier

Abstract

The invention discloses a fully-distributed optical fiber sensor in combination of an optical fiber Raman frequency shifter and a Raman amplifier. After shifting frequency for 13.2 THz by the optical fiber Raman frequency shifter, an optical fiber pulsing laser produces a broad spectrum Raman laser with a 1660nm wave band, wherein the broad spectrum Raman laser is served as the broad spectrum light source of the fully-distributed optical fiber sensor for performing the incidence of a sensing fiber; the deformation and the breaking of the optical fiber can be detected based on the reverse Rayleigh scattering strength ratio of the sensing fiber; the 1550nm wave band produced in the sensing fiber undergoes reverse anti-Stokes Raman scattering and is amplified by the optical fiber Raman amplifier; the temperature information at each section of the optical fiber can be obtained by deducting the influence produced by straining according to the strength ratio of the anti-Stokes Raman scattered light to the Rayleigh scattered light; the inspection on the training and the temperature is out of cross effect; the detection point on the sensing fiber can be located by using an optical time domain reflection technology. The fully-distributed optical fiber sensor is applied to the monitoring of petrochemical pipes, tunnels and large-scale civil engineering within ultra-long range of 100 kilometers, as well as disaster prediction monitoring.

Description

technical field [0001] The invention relates to the field of optical fiber sensors, in particular to a distributed optical fiber Rayleigh and Raman scattering photon strain and temperature sensor. Background technique [0002] The optical fiber sensor network developed in recent years can realize the safety and health monitoring and disaster forecasting and monitoring of large-scale civil engineering, electric power engineering, petrochemical industry, traffic bridges, tunnels, subway stations, dams, embankments and mining projects. There are two types of optical fiber sensors: one is a quasi-distributed optical fiber sensor network composed of point sensors such as fiber grating (FBG) and fiber optic method white (F-P) "hanging" (laying) on ​​the optical fiber and using optical time domain technology , the main problem of the quasi-distributed optical fiber sensor network is that the optical fiber between point sensors is only the transmission medium, so there is a detectio...

AI Technical Summary

Problems solved by technology

However, it has been unable to fully meet the safety and health monitoring of oil pipelines and transmission power cables in recent years, and the urgent demand for long-range and ultra-long-distance fully distributed optical fiber Rayleigh, Raman and Brillouin scattering strain and temperature sensor networks

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