FiberOpticNetworkDesignX.Wu,M.Y.Li,C.S.YanDept.ofOpt.Engr.,ZJU2011Class9&10

FutureOpticalAmplifierDesignofHybridAmplifierGainOptimizationGainBalanceNoiseFigureExerciseWhat’stheNextforOpticalAmplifiers?IntelligentEDFAsEDFAisbacktonormalAmplifiersinMidlife(midlifecrisis?)Fromwiki……Midlifecrisisisatermcoinedin1965byElliottJaquesandusedinWesternsocietiestodescribeaperiodofdramaticself-doubtthatisfeltbysomeindividualsinthe"middleyears"ormiddleageoflife,asaresultofsensingthepassingoftheirownyouthandtheimminenceoftheiroldage.Sometimes,acrisiscanbetriggeredbytransitionsexperiencedintheseyears,suchasextramaritalaffairs,andropauseormenopause,thedeathofparentsorothercausesofgrief,unemploymentorunderemployment,realizingthatajoborcareerishatedbutnotknowinghowelsetoearnanequivalentliving,orchildrenleavinghome.Theresultmaybeadesiretomakesignificantchangesincoreaspectsofday-to-daylifeorsituation,suchasincareer,work-lifebalance,marriage,romanticrelationships,largeexpenditures,orphysicalappearance.CoreNetworkEvolutionCommoditizationofAmplifiersReconfigurableNetworksneedFastGainControlHybridAmplifiersPartICombiningRamanAmplificationwithAmplificationbyEDFAinLonghaulWDMSystemsOutlineOverviewofRamanandEDFAscombinedamplificationHybridamplifierissuesComparisonofdifferentamplifiedsystemconfigurationsGainbalancebetweenRamanandEDFAsOverviewofRamanandEDFAsCombinedAmplificationWhyuseHybridAmplifiersEnlargesthetransmissioncapacityofbroadbandsystems“Upgrading”theexistingsystemsbuiltwithEDFAamplifierswithbroader/flatterbandwidthAbilitytocarrymorewavelength-multiplexedopticalchannelsatgivenspacingamongthechannelsRamanamplificationgivesflexibilitytotheselectedbandamplificationLesssensitivetononlineareffects–systems’point-of-viewBasicIdeaofHybridAmplifiersPrincipleofworking/OperatingModeFlattenEDFAgainbyusingRamangainImprovegainperformanceatlongersignalwavelengthsTypicalConfigurationsRamanAmplifierssetupindifferentconfigurations:DiscreteDistributedbackward-,forward-andbidirectionalpumpednumeroustypesoffibers(DSF,DCFtobeusedasSRSactivemedia)EDFAssetupconsiders:

seriesorparallelconfigurationsingleormultiplefiberstagesC-andL-bandregionsHybridAmplifiersIssuesTheHybridAmplifiersstudiesareconcernedwith:maximizingthespanlengthand/orminimizingtheimpairmentsoffibernonlinearitiesenhancingtheEDFAs’bandwidthdesigning“optimal”hybridamplifiersinordertoobtainflatandwidestoutputgainperformanceComparingDifferentSystemConfigurationResultsObtainedAfterComparingthe3TypesofSystemsConsideringin-lineandpre-amplificationfunctions:Long-haulEDFA-onlysystemsarelimitedbyOSNRandNLeffectsRaman-onlysystemstendtobelimitedbyareductionofSNRcausedbydoubleRayleighbackscatteringCombinationofdistributedRamanandEDFAspresentbetterperformancethanconventionalEDFA-onlysystemsRamancomplementEDFAsinterrestrialhighcapacitylonghaulapplicationsOptimizingHybridAmplifierinaSystemGainBalanceBetweenRamanandEDFAsComplexproblemwithseveraldegreesoffreedom-optimizationtechniqueMainconsiderationstodeterminetheoptimumgainbalancebetweenRamanandEDFAsMostimportantparametersOSNR,gain-flatness,bandwidthnumberofchannels,numberofspans,MaximumtransmissioncapacityFocusingonExtendingtheBandwidthIncreasethenumberoftransmittedchannelsGainflatnessOptimizethehybridamplifierperformanceGain,NF,OSNRTechniquesthatEnlargeFlattenedGain-Bandwidthof“Discrete”FiberAmplifiersI.Newhostmaterialsfluoride-andtelluride-basedEDFAsthulium-dopedfiberamplifierII.UsingEDFAswithGEQ+discreteRamanamplifierIII.Differentamplifierconfigurationstwo-gainbandparallel/seriesconfiguration–multiplefiberstagegain-equalizing(GEQ)filtersTypicalValuesObservedinHybridAmplifiersBandwidth>40nmGain15–25dBGainRipple<11.3%NoiseFigure<6dBOSNR>32dBExamplesofWideFlattenedBandwidthforDiscreteRaman/HybridFiberAmplifierPartIIDesignHybridAmplifierOutline1.Modelsrequiredinthesimulations2.HybridamplifierdesignedtoLAN3.Gainandnoisefigureresults4.Ahybridamplifiersetupinmultiplefiberstages5.CharacterizationandperformanceinasystemModelsRequiredintheSimulationsEDFAModeling:Solverateandpropagatingequationsforpump,signal,andASE,consideringnon-lineareffectspresentinthefiberpropagation.RamanAmplifierModeling:Solvetherateandpropagationequationsforpump,signal,andASEintheRamanfiberamplifierHybridAmplifiersDesignedforLocalAreaNetworks*LANandMANapplications -Gave~20dB -Netgain>10dBDistributedRamanfiberamplifierinserieswitharemotelypumpeddiscreteEDFAC-bandandL-BandWDMsignalinputOptimizeddesignparameters*Karaseketal.,IEEProc.-Optoelectron.Vol.148,No.3,p.150,HybridAmplifierLayout-copropagatingPumpingPowerSettingInputSignalsSettingEvaluatingResultsintheC-bandWavelengthRangeRamanOutputSpectraTotalPowersalongtheEDFAResultsinL-bandWavelengthRangeIn-classExerciseDesignahybridamptoobservegainbalanceaswellasnoisefigure/OSNRequalizationCounter-propagationpumpingv.s.co-propagationpumpingParameters:PumpingwavelengthPumplaserpositionPumpingpowerFiberlength,EffectiveareaRamanamplocationResidualpowerpumpingforEDFA->reduce#oflasersFutureAmplifier:

ExtendingfromC+LtoS,EbandOutlineStandardizationactivitiesinopticalamplifiersTrendsinopticalamplifiersCurrentstandardizationissuesOpticalamplifiers

-Transparencyofphysicallayer-Specificparameters:

Outputpower,Gain,Noisefigure,…-Independentonsignalformats,bitrate,etc-

NRZ,RZ,duobinary,…

OTU1,OTU2,…CooperationwithIECIECrole Selectionofspecificparameters Definitionoftheparameters Testmethodoftheparameters

opticalpower,gain,noisefigure,etc..ITU-Trole

RequirementfromtheviewpointofopticalsystemsbasedonIECdefinitionandtestmethodCooperationwithIEC-SC86C-WG3inRec.G.661Table1/G.661–Recommendedtestmethodsforparametersdefinedinclause4GroupoftestparametersParametersof

clause4involvedTestMethod(TM)–IECBasic

SpecificationnumberGainparameters4.1to4.8,4.10,4.32,4.39,4.4061290-1-1:OpticalspectrumanalyserTM

61290-1-2:ElectricalspectrumanalyserTM

61290-1-3:OpticalpowermeterTMOpticalpowerparameters4.9,4.11,4.12,4.25,4.28,4.2961290-2-1:OpticalspectrumanalyserTM

61290-2-2:ElectricalspectrumanalyserTM

61290-2-3:OpticalpowermeterTMNoiseparameters4.13to4.15,4.33to4.3661290-3-1:OpticalspectrumanalyserTM

61290-3-2:ElectricalspectrumanalyserTM

61290-3-3:PulseopticalTM(understudy)Reflectanceparameters4.16to4.19,4.3861290-5-1:OpticalspectrumanalyserTM

61290-5-2:ElectricalspectrumanalyserTM

61290-5-3:ElectricalspectrumanalyserTM(forreflectancetolerance)Pumpleakageparameters4.20,4.2161290-6-1:OpticaldemultiplexerTMInsertionlossparameters4.22,4.23,4.3761290-7-1:FilteredopticalpowermeterTMRecommendationsandpublicationsforopticalamplifiersITU-TSG15Recommendations G.661:DefinitionandtestmethodsfortherelevantgenericparametersofOpticalAmplifiers G.662:GenericcharacteristicsofOpticalAmplifierdevicesandsub-systems G.663:Application-relatedaspectsofOpticalAmplifierdevicesandsub-systemsandcomprehensiveAppendixontransmission-relatedaspectsIECTC86SC86CPublications Genericspecification Testmethod PerformancespecificationtemplateTrendsinopticalamplifiers

-EDFAvs.Raman-EDFA:Maturetechnology

Newmaterials(Fluoride,Tellurite) Newdopant(Pr,Tm)~PDFA,TDFA

toexhibitbroaderandflattergainRamanamplifier:Advantageinlong-haul(LH)space

SNimprovementbydistributedRaman Flatgainbymultiplepumpwavelength>> EfficiencymeritofEDFAisoffsetbyrequiredgain

flattening.

>> RamansystemsarechallengingEDFAstrongholdinLH

applications.OpticalamplifiertypeRareearth-DopedFiberAmplifiers Erbium-DopedFiberAmplifiers(EDFA) :C,L-Band

Thulium-DopedFiberAmplifiers(TDFA) :S-Band Praseodymium-DopedFiberAmplifiers(PDFA) :O-BandFiberRamanAmplifiers DiscreteRamanAmplifiers DistributedRamanAmplifiers(DRA)SemiconductorOpticalAmplifiers(SOA) conventionalSOA GC-SOA(Gain-ClampedSOA) LOA(LinearOpticalAmplifier)SEEFIRETechnicalWorkshop–Sofia,Bulgaria,14-15

July2005

AmplifierExamplesEDFASOARamanOptical

FibreAmplifiersActiveenvironment–specialfibredopedwithoneormorerareearthelement(Er,Nd,Pr,Tm,…orcombinationEr/Yb,Tm/Yb,..)PDFAPrdoped,suitablefor(1280-1340nm)G>30dB,Pout>16dBm,NF<7dBTDFATmdoped,suitablefor(1440-1520nm)G>30dB,Pout>20dBm,NF<7dBErbium-DopedFiberAmplifiers

CharacteristicsMostwidespreadintelecommunicationsSuitableforCband(lowestfiberattenuation)commonsilicaglassAdvantagesOperatingrangein1520-1610nmG>45dB,Pout>37dBm,NFin<3.5,7>dBMulti-channelcrosstalkverylowPolarizationindependentDisadvantagesNotsmalldevices,cannotbeintegratedwithothersemiconductorsGainspectrumnotinherentlyflatRamanAmplifiers

CharacteristicsBasedonsimulatedRamanscattering,activeenvironment–common(non-doped)fiberG

in<10,15>

dB,Pout>30dBm,NF<1dBAdvantagesUsablein1250-1650nmregionsBandwithcanbetailored(1pump35nm,morepumpupto90nm)LowerNFthanEDFAHighprocessefficiencyinDCF(loss->gain)componentDisadvantagesHigherinterchannelcrosstalkthanEDFAHighpumppowers(safetyissues)SemiconductorOpticalAmplifiersBasedonconventionallaserprinciple,activeenvironment–waveguideregionsandwichedbetweennandpregionsG>25dB,Pout>15dBm,NFin<7,10>dBAdvantagesUsablein13101550nmregionsWideband(40-80nm)Smallcompactsemiconductors,easytointegrateDisadvantagesHigherNFthanEDFAHigherinterchannelcrosstalkthanEDFAPolarizationsensitiveSpectralusabilityofAmplifiersOSCLAmplifiersfor(D)WDMIEDFA–needsgainflatteningGlasscomposition(F,Teglasshost)SinglestageEDFA,silicahost:bandwidth15nmSinglestageEDFA,fluoridehost:bandwidth25nmEqualizersTwostage,silicaorfluoridehost,nogainflattening:30nmTwostage,silicahost,gainflattening:50nmTwostage,telluritehost,gainflattening:80nmHybridOAMulti-arm-twobandoperation,silicahost:85nmAmplifiersfor(D)WDMIIHybridEDFA/RamanBandwidthcanbetailored~80nmLowerNFthanEDFAseparate!!OSNRimprovement

Rareearth(Er,Tm,Pr)-DopedFiberAmplifiersGainband:

Er(C,L-Band),Tm(S-Band),Pr(O-Band)

76nm(1532-1608nm)recordgainbandwidthinsinglebandconfiguration[M.Yamadaetal.,OFC’98PD].

-Flatgain:21dB,Noisefigure:7dB

-Gainequalizer:twoMZfilterswithFSRof32and120nmSemiconductorOpticalAmplifiersGainband:

1.3~1.7um(tunablebyInGaAsPcomposition)

Maximumgainbandwidth:~100nmConventionalSOA SufferingfromgainrippleandXGM-inducedcrosstalkoriginated fromgaindynamics(relaxationoscillationetc.) ->Notapplicabletohigh-speedorwide-bandsignalsGC-SOA(Gain-clampedSOA): Gainstabilizationbyanadditionallasingoscillationwhichlocksthe carrierdensity. >Excellentlinearity(lowXGM) >>high-speedorwide-bandapplicationsFiberRamanAmplifiersGainband:1.3~1.7um(tunablebypumpwavelength)132nmrecordgainbandwidth

indoublebandconfigurationhasbeenachieved[H.Masudaetal.,ECOC’99].

-CombinationofDistributedRamanamplifiers(DRA)anddiscreteRaman -Two-gain-bandRamanamplifierGainprofileofhybridDRA132nmRecordGainBandwidthinDouble-BandConfiguration-2520151050-5-10Gain(dB)1650160015501500Wavelength(nm)91nmdistributedgaindiscretegaintotalgainfiberloss41nmHirojiMasuda’swork(NTT)HirojiMasuda’swork(NTT)Type2Type4HirojiMasuda’swork(NTT,2000)BERperformanceoftheType-2testedina9x2.5Gb/sWDMThesignalpowerlaunched5dBm/total=-4.5dBm/channel.ErrorfreeoperationwithBERsunder10-11

3-dBgain-bandwidthsofupto82.