Research On Dual-parameter Of Distributed Optical Fiber Sensing System Based On Brillouin Scattering

The fiber sensor technology has been froming with the optical fiber communication,and thefiber sensor has many advantages which can’t be found in ordinary sensors.Distributed opticalfiber sensor is the use of light in the fiber transmission characteristics,the length direction ofoptical fiber sensor is continuously measured parameters (temperature, pressure and stress,etc.),so it has been paid great attention in the current scientific research. Because distributedoptical fiber sensing technology which based on optical time domain reflectometer (OTDR)technology and Brillouin optical frequency domain analysis (BOFDA) has been perfecting.Butbased on Brillouin optical time domain reflectometry (BOTDR) distributed optical fiber sensingtechnology is still in-depth study,so it has wide using area and development space.This paper briefly introduces the development and research status of optical distributed fibersensing, scattering distributed fiber optic sensors,and the research status of temperature andstrain based on Brillouin scattering sensing research at the same time. Detailed description of thesensing mechanism with Brillouin scattering, Brillouin scattering distributed fiber sensing-basedclassification and characteristic parameters.Then the influence of temperature and strain aboutthe brillouin scattering on the system is theoretically analyze, the corresponding relationsbetween the Brillouin frequency shift and intensity with temperature and strain is deduced onthis basis, finally draw the temperature and strain measuring simultaneously relation withBrillouin frequency shift and intensity.Through the detailed theoretical analysis,put forward a new kind of simultaneousmeasurement system of temperature and strain based on Landau-Placzek Ratio(LPR).TheBOTDR signal of the system is simulated from Matlab, and the BOTDR sensing systemperformance has made the detailed analysis. According to the theory of the system calculated thesignal-to-noise ratio, and the the resolution of temperature and strain.At last,this paper do adetailed analysis and research about the spatial resolution of the sensor system, dynamic rangeand measuring the time.