分布式光纤温度传感器的设计和优化

上海交通大学硕士学位论文分布式光纤温度传感器的设计和优化姓名：周正仙申请学位级别：硕士专业：电子与通信工程指导教师：肖石林20090505V207012VI34567AbstractVIIDesignandOptimizationofDistributedOpticalFiberTemperatureSensorAbstractThetechnologyoffiberopticdistributedsensingwasbroughtforwardintheendof1970’s.Sincethenaseriesofdistributedsensingsystemsbasedondifferentmechanismwerestudiedandusedinmanyfieldsgradually.Nowadays,thishasbeenoneofthemostpromisingtechnologiesinfiberopticsensor.Thefiberopticdistributedtemperaturesensorsystemcansensethechangeoftemperaturealongtheopticalfiberbytheformofcontinuousfunctionofdistance.Thefiberusedinfiberopticdistributedsensorisnotonlytransportmediabutalsosensingmedia.Ithasthecharacteristicsofresistancetoelectromagneticinterfere,againstfire,smallsizeandlittleeffecttotemperaturefield.ThebackscatteringRAMANsignalwiththeinformationoftemperatureisquiteweakandevencompletelysubmergedinnoise.Themeasurementaccuracyofthewholesystemhasrelationshipwiththedenoisingleveltoanti-StokesandStokesbackscattering.Weaksignalmeasurementismustbeusedinthissystem.ThisdissertationtakesAbstractVIIIdeepresearchandanalysisonthefiberopticdistributedtemperaturesensor.Themaincontributionsareasfollows:(1)TheRAMANscatteringinopticalfiberisanalyzedandtherelationshipbetweenRAMANscatteringandthetemperatureoffiberinthesensingfieldisstudied.Furthermore,therelationshipbetweenanti-Stokeslightandtemperatureinpracticaluseisestablishedwhichhasimportantinstructionalsignificancetothedesignationoffiberopticdistributedtemperaturesensor.(2)Thecentralwavelengthisdiscussedbasedonthecombinationofsignal-to-noiseratio,temperaturesensitivityofsystemandoperatingstability.(3)Anexcellentdrivingcircuitoflaserwasdesigned,whichcancontroltheshapeandwidthofimpulselighteffectivelyandensurethecharacteristicofdistributedfiberoptictemperaturesensorsystem.(4)Eachpartofsystemisanalyzedandresearchedbasedonthecharacteristicsofdistributedfiberoptictemperaturesignal.(5)Spatialresolutionofthesystemisresearched,andgetthemethodofimprovethespecialresolution.(6)Temperatureresolutionofthesystemisresearched,andgetthemethodofimprovethetemperatureresolution.(7)Stabilityofthesystemisresearched,andgetthemethodofimprovethestability.AbstractIXKeywordsOpticalfibersensor,Opticalfiberdistributedsensor,Opticalfiberdistributedtemperaturesensor,Opticaltime-domainreflectometer,RAMANscattering,RAMANwavelength-divisionmultiplexingIIIIV11.1[1][2][3]2[4][5][6][7][8](1)(2)(3)(4)1.220603(1)(2)(3)(4)(5)20807041.2.11.2.1.1NnnN[9][10](1)(2)[11]1.2.1.2[12][13]OTDROpticalTimeDomainReflectometry[14][15][16](1)(2)RAMAN(3)(4)Rayleigh(5)5(6)(7)(8)(9)Brillouin(1)(2)Kerr(3)(4)1.2.2123,1980OTDR6OTDR1983100111995Dieter30km15m1985J.P.Dankin1986YorkDTS8008km1m10.340004km20sDTS-Ultra30km22m30km1990Paton0.5km337nm0.5m1992Ryozo7km3m13km3m31993Namkung1.2km5m1996Jansen,199910km8m57OTDRROFDRROFDROFDR19981.3OTDROTDROTDROFDROTDROFDROTDROFDROFDR20dB~30dBLD8StokesStokesStokes50/125mNA=0.21pWAPD2km4cm1988SPIEOTDR9APD1.41.4.11.4.21234RWDM56AD78109112.1OTDR2.2OTDROTDR,,1976M.BarnoskimM.JensenOTDR,,,,,,,,12,,,,2.2.1,,()410mX,()4013E.M.C.R.r,,1928()()2-114()(),)cos12θ+,θ,,=400mm=700nm0.53.5151)(θI41λ2-2)(θIθ2)(θI)cos1(2θ+2-12-1θFig.3-1Relationshipofscatteringlightintensityandθ3xeyzeeyz16exeypepxθ0z'AAAz==θθcoscos'0yAAAy==)(θI)cos1()cos1('')(2220θθθ+=+=+=iyzIAIII2-32-2θ=0θ=πyz'yA'yAyA2-2Fig.2-2Swingofscatteringlight17θ)cos1()(24220θλαθ+=iIrVNI2-4α2n1n12nn=0=α0≠α0NVrλiI)(θI41λ2-5)cos1(2θ+2.2.2OTDR,,,,;,(0.0001)OTDR0PZ()Pz180()azPzPe−=⋅2-6aNp/Km,dB/Km,:1dB/Km=4.35Np/Km2-7,(2-6)P(z)P(z),r()()dPzrPzdz=2-8()Pt200()LazPtrPedz−=⋅∫2-912gLvt=⋅2-10gvr2222013()2()NArVnaω=2-11122212()NAnn=−,1n2n0ω,a,V(2/)VaNAπλ=2.2.3OTDR,OTDR,OTDR2-3,(10ns~400ns),,192-3OTDRFig.2-3TheprincipleofOTDR(2-12)(2-13)OTDROTDR,,DtDZ1122CZttnν=⋅⋅=⋅⋅2-12νnCt∆t[z()/2ztυ+∆]OTDR2tZυ•∆∆=2-13,,OTDR,202.3,,,,,OTDR2.3.1,v=12‐42-4Fig.2-4RelativisticenergylevelsofRAMANscatteringv0+vhv0E2E1hv0v0-vv021E1E2v0hv0E1(E2)E1+hv0(E2+hv0)E1(E2)v0(RayleighScattering)E1,E2h(v0‐v),v0–v(StocksScattering)E2hv0,E1h(v0+v),v0+v(Anti‐StocksScattering)2‐52-5Fig.2-5SpectrumofRAMANscattering2.3.2Stokes2-14Stokes222-152-16NeKsKASKRStokesStokesSAS,sStokesStokes00,AS,sStokesStokesLRs(T)RAS(T)2-172-18hk2.4RAMAN232.4.1Anti-Stokest=t0T=T0LAnti-StokesRAMAN2-19tT(2-3)(2-6)2-201K(2-8)hkT0NAS(T)/NAS(T0)TLD2.4.2Anti-StokesStokes0TT=24])(exp[)exp(1)exp(2)(00000LThThEvTPASASASαακνκν+−Γ∆−−∆−=2-21])(exp[)exp(112)(0000LThEvTPSSSαακν+−Γ∆−−=2-22])exp[()exp()()(000LThTPTPASSSASSASαακν−ΓΓ∆−=2-23T])(exp[)exp(1)exp(2)(00LThThEvTPASASASαακνκν+−Γ∆−−∆−=2-24])(exp[)exp(112)(00LThEvTPSSSαακν+−Γ∆−−=2-25])exp[()exp()()(LThTPTPASSSASSASαακν−ΓΓ∆−=2-26)exp()exp()()()()(000kThThTPTPTPTPSASSASνκν∆−∆−=2-27(3.2.2.4.2.3‐5)])()()()(ln[0000TPTPTPTPThThTSASSASκνν−∆∆=2-282-232-28RPASPSP25v0Ehκν∆RΓASΓSΓ0αASαSα()LT(2-28))exp()exp()()()()(02002ThThThdTTPTPTPTPdSSASSASκνκνκν∆−∆−∆==2-2901200.862%/2.4.3Anti-StokesRayleighRayleighOTDRAnti‐StokesRAMANOTDRStokes262-30T=T02-312‐31T02‐31T2.52-6Fig.2-6ZoneSelectionfortemperaturecalibration2-6100027180m200m2.6OTDR283.1RayeighBrillouinRAMANR