光放大器基本原理和特性ppt课件.ppt

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1、光放大器基本原理和特性OutlineIntroductionErbium-dopedfiberamplifier(EDFA)RamanAmplifier(RA)SemiconductorOpticalAmplifier(SOA)Introduction一、光电中继器（O-E-O）装置复杂、耗能多、不能同时放大多个波长信道，在WDM系统中复杂性和成本倍增，可实现1R、2R、3R中继二、光放大器（O-O）多波长放大、低成本，只能实现1R中继三、光放大器类型：掺杂光纤放大器（EDFA、PDFA）半导体光放大器（SOA）非线性光纤放大

2、器（FRA、FBA）光纤参量放大器（FPA）四、发展历程：80年代中、后期SOA的研究为主；90年代EDFA获得巨大成功，成为光纤通信系统必不可少的器件ApplicationsofOpticalAmplifiersIn-lineamplifiersreplacesregeneratorsPoweramplifiersboostsignalstocompensatefibrelossesPreamplifiersboosttherecievedsignalsLANamplifierscompensatedistributionl

3、ossesinlocal-areanetworksRecentProgressandRequirementsBroadBandHighGainFlatBWLowNoiseHighPowerHighReliabilityLowCostCompactnessEDFAErbium-dopedfiberamplifier掺铒光纤放大器EDFAEDFAhasrevolutionizedopticalcommunicationsAllopticalandfibercompatibleWidebandwidth,20~70nmHighgai

4、n,20~40dBHighoutputpower,>200mWBitrate,modulationformat,powerandwavelengthinsensitiveLowdistortionandlownoise(NF<5dB)METASTABLESTATEPumpPhoton980or1480nmSIGNALPHOTON1550nmErbiumDopedFiberAmplifierFUNDAMENTALSTATEFUNDAMENTALSTATEEXCITEDSTATETRANSITIONAmplifiedSignal1

5、550nmEDFAChallengesGainFlatteningGainTransientGainBandwidthWideningGainFlatteningGainSpectrumPopulationatdifferentlevelsaredifferentresultinggaindependenceonwavelengthDifferentpumpinglevelhasdifferentspectrumNon-UniformGainAccumulationGainFlatteningPassiveequalizati

6、onPre-equalizetheinputsignalAdddopant:fluoridebasedEDFABroadbandfilterHybridpumpActiveequalizationAcousto-OpticTunableFilter(AOTF)GainflatnessSilicafiberof20dBgain1dBvariationover20nm,2.5dBover30nmFluoridefiberof20dBgain1.1dBover30nmFluoride-BasedEDFANaturallyFlat.P

7、umpedonlyat1480nmNoisier,brittle,difficulttosplicewithtypicalfiberPassiveGainEqualizationCannotrespondtodynamicchangeinthenetwork:linkloss,routing,reconfiguration...MustknowtheexactspectralshapeofgainLong-PeriodFiberGratingFilterDifferentlengthoffiberhasdifferentgai

8、nspectrum.Needseparatedesign.Widertheflatness,thehigherthelossforsomewavelength.3timeshigherfor40nmwidegainspectrumcomparedwith33nm.Penalt