FiberOpticNetworkDesignX.Wu,M.J.Li,H.M.YanDept.ofOpt.Engr.,ZJU2011Class3Outline

ChromaticdispersioneffectDispersioncompensatingtechniquesOptimizationofresidualdispersionoritsmap010011timefcarrierfreq.ViVjVkFourier?InformationBandwidthofData?TemporalSpreadingf(distance,(bitrate)2)(ps/nm)/kmtimeFibertimePhotonVelocity(f)=SpeedofLightinVacuumIndexofRefraction(f)SignalDegradation

ControlPacket(C.P.),notpayload,isregeneratedateverynodeC.P.haslowerbit-rate(C.D.effect(bit-rate)2)ThereishigherchanceforpayloadtobedegradedNodeNodeNodeNodettttPayloadC.P.EffectonPayloadandControlPacketPolarization-mode-dispersion(PMD)Polarizationdependentloss(PDL)Degradationbasedonnon-catastrophiceventsRandompolarizationcouplingStatisticallyvarieswithtimeBit-rateandwavelengthdependentPolarizationstategenerallyunknownandwandersPMDImpairmentcrosssectionEllipticalFiberCoresideview

PMDinducesrandomlychangingdegradations.Criticallimitationat

10Gbit/spayloaddatarates.The2polarizationmodespropagateatdifferentspeeds.1st-orderPMD=DGDPMD(A)(B)DGDPMDCausesandStatisticalEffectHowmanysegmentswillbeenoughtoemulatePMD?Ans.=~12PoincareSphere&PrincipleStateofPolarizationPrincipleStateofPolarizationProved1986BellLabsC.D.Poole&R.E.WagnerTwoPSPperpendiculartoeachotherindependentofwavelengthtothefirst-orderPSPinPoincareSphere&PrincipleStateofPolarization球面上的每一個點都代表了一種橢圓偏振態，在兩極演化為右旋、左旋圓偏振光，在赤道退化為線偏振光，北半球為右旋偏振態，南半球為左旋偏振態。所以，偏振光在光纖傳輸過程中的任意偏振態的變化都可以表示成邦加球上的某一條運動軌跡

PMDtemporalchangesmorerapidlywiththefiberlengthandaverageDGDFrequencyofoccurrenceinducedbyPMDfluctuationTimeSpan(ms)Occurrence52kmfiber<>=2.8ps(b)FastFluctuation

Mechanicalvibrations:millisecondstominutesH.Bulow,etal.,OFC1999TimeRateofPMDChangePMD(ps)1.52.02.5101418Temp.(C)Time(min)040080048.8kmburiedcable(a)SlowFluctuation

PMDvariationsduetotemperaturechanges:hourstodaysJ.Cameron,etal.,OFC1998PMDMonitoringTechniquesRequireshigh-speeddevices(demonstratedfor160Gb/sRZsignal)Affectedbyotherdistortionsources+CanbeintegratedwithelectronicequalizationA.EyeopeningmeasurementB.RFspectrumanalysis

+Nohighspeedelectronics+DependsonlyonPMD+Bit-rateindependent+UnaffectedbyotherdistortionsourcesPulse-widthdependentC.

Degreeofpolarization(DOP)measurement+SimpleAffectedbyotherdistortionsourcesSensitivityandDGDrangedependsonmonitoredfrequencyPMDonaninstalledfiberlinkGoalTogainanunderstandingofthetemporalandspectralcharacteristicsofPMDonaninstalledfiberlink.ApproachMakelong-termmeasurementsofthedifferentialgroupdelay(DGDor)overarangeofwavelengthsandassessitsratesofchangewithtimeand.DesiredoutcomeProvidenetworkoperatorswithknowledgetoevaluatetechniquesformitigatingPMD-inducedoutageswhenchanneldataPCforRemoteControl&DataStorageTunableLaserSource(TLS)(1510–1625nm)Dl=0.1nmPolarizationAnalyzer(PA)(JonesMatrixEigenAnalysis)InstrumentController

Fiberloopback:95-kmspan

ofslotted-core,directburiedfiber-opticcablemadeavailablebySprint.Over86days(fromNovember9,2001thruFebruary2,2002)692measurementsweremadeonthe1150discretewavelengths.Measurementswererepeatedaboutevery3hours.PMDCharacterization86daysofdata795,800dataptsObservationsDGDdependsonbothtimeand.DGDvariesslowlywithtime.DGDvariesrapidly

with.InstancesofhighDGDarespectrallylocalized.PMDcharacterization:DGDvs.landtimePMDcharacterization:Probabilitydensityfunction

ObservationsMeasureddatashowgoodagreementwithMaxwelliandistribution.ThereisalowprobabilityofhighDGDevents(i.e.,DGD>3meanDGD).Theoreticalresultsfromoutagemodel:RxThreshold 3<DGD> 3.7<DGD>Span1MTBO 6.39years 1648years!!!Outageduration136minutes 108minutesMTBOs:meantimebetweenoutagesPMDcharacterization:resultsandconclusionsFiberSim:

SMF/LeafComparison75km75km10Gb/sperchannel25channels75kmDCF/EDFADCF/EDFA...DCF/EDFARxTxDifferentFibers:

EyeDiagramsvs.Distance@75km@450km@750km@1050kmSSMFLinkNZDSFLinkCompensationConfigurationsOutputInputSqueezers(00)Squeezers(450)OpticalFiberABCDEPMFEfficientopticalmodulationformats:WDM+SCMOpticalMUXAdd/dropTransmitter1f1Sf2ch.2fnch.n..l1LDch.1lml1f1Sf2ch.2fnch.n..Receiver1ch.1OpticalDMUXf1Sf2ch.2fnch.n..Receivermch.1Transmittermf1Sf2ch.2fnch.n..lmch.1LDEfficientopticalmodulationformats:

CombatPMD-inducedsignalfading

usingdiversitySCMreceiverTxPolarizationcontrollerRFdetectionSLPFAmp.ControlalgorithmTodecisioncircuitSpliterPBSRFdetectionPD1(b)P