光纤通信技术：Chapter 1 Introduction

Chapter1IntroductionVocabularyChapter12SOEI,HUSTNearinfrared近红外DWDM:densewavelengthdivisionmultiplexing密集波分复用Modulationformat调制格式Regenerator再生器Repeaterspacing中继距离Bitrate-distanceproduct比特率距离的乘积Dispersionshiftedfiber色散位移光纤Submarinetransmissionsystem海底传输系统Dryfiber无水光纤Opticalsoliton光孤子Binaryrepresentation二进制表示方法Samplingtheorem抽样定理Nyquistcriterion奈奎斯特准则Quantizationnoise量化噪声PPM脉冲位置调制PDM脉冲宽度调制PCM脉冲编码调制TDM时分复用FDM频分复用Digitalhierarchy数字体系SONET同步光网络SDH同步数字体系STM同步转移模块RZ归零码NRZ非归零码CSRZ载波抑制归零码AM/FM/PM幅度/频率/相位调制ASK/FSK/PSK幅/频/相移键控OOK：通断键控Free-spaceopticalcommunication自由空间光通信系统Opticaltransmitter光发射机Launchedpower发射功率IM/DD强度调制/直接探测BER误码率Receiversensitivity接收机灵敏度Quantumnoise量子噪声Shotnoise散粒噪声Thermalnoise热噪声1.1 SystemConfiguration&SystemComponents1.2HistoricalEvolutionReview1.3BasicConceptsChap1IntroductionChapter13SOEI,HUST1.1.1GeneralRemarksChapter14SOEI,HUSTCommunicationOpticalCommunicationOpticalFiberCommunicationCarrier:MicrowaveOpticalwaveMedium:FreespaceOpticalfiber

TelegraphTelephoneRadioCableTVWireless….1.WhatIsOpticalFiberCommunicationChapter15SOEI,HUST

Carrierfrequency→BitrateMicrowave→300MHz~3GHz→B~100Mb/sOpticalwave→200THzat→B~10Tb/stimes!2.WhyUsingOpticalCarrier?Chapter16SOEI,HUSTAdvantagesLowlossinvisibleandnearIRspectralregionsSignalwellprotected&immunetoelectricalinterferenceLowcost(silica)Small:125mmouterdiameter(ductspace);lightNoteasytobecorrodedDisadvantagesDifficulttocoupleandsplitDifficulttoconnect:fusedsplicingUnabletobendsharplyEasytobreakLoss→Distance(L)CapacitydefinedasB*L(Bit-ratedistanceproduct)3.WhyUsingOpticalFiber?Chapter17SOEI,HUSTWavelength:µm=10-6m,nm=10-9m,pm=10-12mBandwidth:MHz/GHz/THz,100GHz~0.8nm(1550nmwindow)Decibelpowerunits:1mWcorrespondsto0dBm1µWcorrespondsto-30dBm1Wcorrespondsto30dBm4.ImportantUnits1.1.2SystemConfiguration&SystemComponentsChapter18SOEI,HUSTReamplifyRetimeReshapeRepeaterOpticalReceiverElectricalReceiverData/Audio/VideoO/EOpticalTransmitterElectricalTransmitterData/Audio/VideoE/OO/E/OorO/Ofiberfiber1.SystemConfiguration96x40/100Gbit/sT-bit级光传输系统Chapter19SOEI,HUSTBinarytosingleCoding/linecodingModulatorOpticalSource(LDorLED)DrivingCircuitPCMChannelcouplerOpticalsignaloutputLD/LEDLaunchingPowerSpectralLinewidthNarrowLinewidthLaserOpticalTransmitter2.SystemComponentsChapter110SOEI,HUSTFiberLossFiberDispersionFiberNonlinearity&High-orderDispersionFiberspoolOpticalFiberChapter111SOEI,HUSTRepeater3R:ReamplificationRetimingReshapingO/E/O3R:nottransparenttodataformat,speedetc.O/O3R:opticalamplifier,dispersioncompensation

OpticalRepeaterChapter112SOEI,HUST

EDFASOAChirped

Bragggrating••

•

llonglshortG.652:PositiveDispersion@1550nmDCM

OpticalAmplifier

DispersionCompensationModule(DCM)Chapter113SOEI,HUSTChannelcouplerPhotodetector(PINorAPD)PreamplifierLinearchannelDecisionSingle-binaryDecodingPCMsignalOpticalsignalinputNosie&sensitivity!2.5Gb/sAPD

10Gb/sPIN

OpticalReceiver1.1 SystemConfiguration&SystemComponents1.2HistoricalEvolutionReview1.3BasicConceptsChap1IntroductionChapter114SOEI,HUST1.2.1HistoricalPerspectiveChapter115SOEI,HUST1.EarlytimeFire，smokesignalsOpticaltelephone(Bell,1880)opticalsource:notstableandreliablemedium:largelossLaserdiode(opticalsource)Fiber(medium)1960Maimanrubylaser1962LD（GaAs870nm)1970sLDatroomtemperature(GaAsAl850nm)1310

,1550nmmultimodeLDsinglelongitudinalmodeLD1951medicalfiber

(1000dB/km)1965E.Millerlenswaveguide1966

Loss<20dB/km(高锟)1970Corningfiber(20dB/km)0.5dB/km@1310nm,0.2dB/km@1550nmSinglemodefiber(SMF)Shorttolongwavelength

multimodetosinglemodeK.C.Kao高锟2.MilestonesChapter117SOEI,HUST1st:LD:multi-longitudinalmode(MLM)Fiber:multimodefiber(MMF)Wavelength:0.85µm(3.5dB/km)2nd:LD:MLMFiber:MMF→singlemodefiber(SMF)Wavelength:1.31µm3rd:LD:MLM→SLMFiber:SMF→DSFWavelength:1.55µm4th:Wavelengths→WDM5th:Multi-levelmodulationformat,S+Lband,Ramanamplification,Coherentdetection,Dispersion&NonlinearityManagement3.SeveralGenerationsChapter118SOEI,HUST196619701980199520012015theoryLDoperateatCW,roomtemp.Singlemode,longwave-lengthLDWDMAdvancedmodulationformatUltra-high

speedUltra-large

capacityUltra-longdistanceLoss/dispersionnonlinearitySpectralefficiencySpectralefficiencynonlinearityLoss/dispersionThreekeyissuesdrivetransmissionsystemrevolutionnonlinearityChapter119SOEI,HUSTFunctionalityYear199420002006opticalamplifierspoint-to-pointWDM&DWDMDWDMpoint-to-multipointStaticOADMsdynamicOADMs

e-g-STM1ondemandColouredsectionringsOXCandDXCco-existencewavelengthconversionWavelengthroutingOpticalpacketswitchingConnectivityCapacityFlexibility4.Point-to-pointtowardsOpticalNetworking20FibersconnecttheworldChapter1SOEI,HUST1.1 SystemConfiguration&SystemComponents1.2HistoricalEvolutionReview1.3BasicConceptsChap1IntroductionChapter121SOEI,HUST1.3.1Analog&DigitalSignals Chapter122SOEI,HUSTAnalogsignals:audio,video(continuous)Digitalsignals:data(discrete,binaryrepresentation)

AnalogSignalDigitalSignalLightwavesystemsusedigitalsignal!1.WhatAreAnalogandDigitalSignals

Chapter123SOEI,HUSTSignalcanberecoveredevenincaseofnoiseanddistortion!2.BenefitsofDigitalSignal

Chapter124SOEI,HUSTThreesteps:SamplingQuantizationCoding3.AnalogtoDigitalConversion(ADC)

Chapter125SOEI,HUST(NyquistCriterion)tominimizeadditionalnoise:M>Amax/AN(quantizedsignallevel)SNR=20log10(Amax/AN)(signal-to-noiseratio)ConsiderBinarycoding:(mbitspersample)Bitrate

RequirementoftransmissionbitrateSampling:Quantization:Coding:Amax:themaximumamplitudeofthegivensignalAN:theroot-mean-squarenoiseamplitudeoftheanalogsignalChapter126SOEI,HUSTDigitalAudioSignal∆f=3.1kHz(300Hz~3.4kHz),SNR=30dBB>31kbit/sInpractice,fs=8kHz,m=8bits/sampleB=64kbit/sDigitalVideoSignal∆f=4MHz,SNR=50dB(HDTV)B>66Mbit/sInpractice,fs=10MHz,m=10bits/sampleB=100Mbit/sExamplesChapter127SOEI,HUSTRZ(return-to-zero)clockforretimingrequirelargebandwidthNRZ(non-return-to-zero)smallbandwidthbit-pattern-dependenteffectDigitalbitstream010110…codedbyusing(a)RZand(b)NRZformats.4.DigitalDataFormat:RZandNRZ1.3.2ModulationandMultiplexingChapter128SOEI,HUST1.RepresentationoftheElectricalFieldofOpticalSignalPolarizationSpatialdistributionAmplitudeFrequencyPhaseTimeChapter129SOEI,HUSTAMFMPM,,areanalogsignals,correspondingtoAM,FMandPMmodulation(carrier)×AMsignal=2.ModulationFormatsAnalogmodulationChapter130SOEI,HUST,,aredigitalsignals,correspondingtoASK,FSKandPSKmodulationASKPSKFSKASKFSKPSKElectricalbinarydataOpticalsignalBasicdigitalmodulationtechniquesChapter131SOEI,HUSTPolSKQAM:QuadratureAmplitudeModulationMoredigitalmodulationtechniquestx-pol.y-pol.OOK(ASK)BPSKDPSKQPSKDQPSKMulti-levelQPSK16QAMChapter132SOEI,HUSTtotalnumberofsymbolscontainedbymodulationformatsymbolratebitrateBit:measureofinformationcapacityOOK:BPSK/DPSK:QPSK/DQPSK:16QAM:(Equalprobability)Bitrate(bit/s)andSymbolrate(Baud=Symbol/s)Frequency(wavelength)divisionmultiplexing(FDMorWDM)Chapter133OEI,HUSTTDMFDMorWDM10101Channel1Channel210101101011010112t12Channel210101Channel1

110011001110101t1Timedivisionmultiplexing(TDM)3.ChannelMultiplexingChapter134SOEI,HUSTETDM:electricaltimedivisionmultiplexingOTDM:opticaltimedivisionmultiplexing(moredetailsinchapter6)Formultiplexing24digitalvoicechannelsintoaframe,eachvoicechannelis64Kbit/s(8KHz*8bits/sample),theaggregatebitrateis:24*64KHz=1.536Mbit/sFrame(8000Framesper1second~8kHz)1242channelETDManditsdigitalhierarchyChapter135SOEI,HUST64Kb/s1544Kb/s2048Kb/s6312Kb/s32064Kb/s97728Kb/s397200Kb/s44736Kb/s274176Kb/s8448Kb/s34368Kb/s139264Kb/s564992Kb/s24304753464444JapanUSAEurope,ChinaExtracontrolbitaddedto1.536Mbit/s

PDH:Pseudo-synchronousDigitalHierarchyChapter136SOEI,HUSTSONET(US)Linerate(Mb/s)SDH(ITU-T)OC-1929953.28STM-64OC-964976.64OC-482488.32STM-16OC-361866.24OC-241244.16OC-18933.12OC-12622.08STM-4OC-9466.56OC-3155.52STM-1OC-151.84

SDH:SynchronousDigitalHierarchyChapter137SOEI,HUSTPDM:polarizationdivisionmultiplexingMDM:modedivisionmultiplexingf

MoremultiplexingtechniquesfABCEGIDFHJx-pol.y-pol.WDMchannelsWDMchannelsChapter138SOEI,HUSTPolarizationSpaceT