雨课堂学堂在线学堂云光纤通信技术(成都信息工程大学)单元测试考核答案

目录：Chapter1OpticalFiberCommunicationSystemChapter2OpticFiberWaveguidesChapter3OpticalSourcesandAmplifiersChapter4LightDetectors第1题Weusethetermoptictorefertofrequenciesintheinfrared,visible,andultravioletportionsofthespectrum.Visiblewavelengthsextend______.Afrom0.4micrometerto0.7micrometerBfrom0.4micrometerto0.85micrometerCfrom0.7micrometerto0.85micrometerDfrom1.26micrometerto1.75micrometer第2题Theadventoflampsallowedtheconstructionofsimpleoptic-communicationssystems,anytypeof()isbasicallyanoptic-communicationssystem.AlampBindicatorlampClaserDneonlamp第3题Itwasnotuntil1970thatthefirsttruly()wasdevelopedandfiberopticcommunicationsbecamepractical.AfiberBlow-lossfiberCplasticfiberDmultimodefiber第4题Digitalmodulationinvolvestransmittinginformationindiscreteform.()第5题Inanycase,theinformationmustbeinopticalformbeforetransmissionforeitherelectronicoropticalcommunications.()第6题Assumingthatthelossofthesystemis-3dBandtheinputpoweris5mW,theoutputpoweris2mW.()第7题Inwhichphenomenondoestheparticlenatureoflightmanifest?AInterferenceanddiffractionBPhotoelectriceffectCBraggscatteringDPropagationofelectromagneticwaves第8题Inwhichphenomenondoestheparticlenatureoflightmanifest?AInterferenceanddiffractionBComptonscatteringCBraggscatteringDDeviationinamagneticfield第9题Inanexperiment,abeamoflightpassesthroughanarrowslit,formingadistinctinterferencepattern.Basedonthisobservation,lLightisaparticlebecauseonlyparticlescanforminterferencepatternswhenpassingthroughanarrowslit.第10题Theparticlenatureandwavenatureoflightaremutuallyexclusive第1题Thefiberopticlong-distancenetworkinChinaisashighasA58%B68%C88%D98%第2题Thefirstopticalfiberusedintransmissionsystemwasinventedin1970.第3题Therelativerefractiveindexdifferencebetweenthecorerefractiveindexn1andthecladdingrefractiveindexn2isdefinedAn1-n2Bn1/n2C(n1-n2)/n1D(n1-n2)/n2第4题Themeridianplaneisdefinedastheplaneintersectingwiththefiberaxisandperpendiculartothefiberwall.第5题ThefollowingthreeformsofsteprefractiveindexfibersarerankedfromlargesttosmallestrefractiveindexstepasfollowsAAll-glassfiber,PCSfibers,All-plasticfiberBAll-plasticfiber,All-glassfiber,PCSfibers,CPCSfibers,All-plasticfiber,All-glassfiber,DAll-plasticfiber,PCSfibers,All-glassfiber,第6题Theopticalfiberwithlargernumericalapertureismoresuitableforapplications.第7题Whatisthemaineffectoftheabsorptionlossofopticalfibersintheshortwavelengthregion?AInfraredabsorptionBUVabsorptionCBendingattenuationDMeltingattenuation第8题Theintrinsicabsorptionattenuationcanbereducedbyreasonablyselectingthedopingmaterialoftheopticalfiberinthemanufacturingprocess.第9题Whichofthefollowingisnonlinearscattering?ARayleighscatteringBMilescatteringCBrillouinscatteringDOpticalscattering第10题Athighpowertransmission,stimulatedRamanscatteringandstimulatedBrillouinscatteringinthefiberwon'tresultinconsiderablelosses.第11题Whichofthefollowingisnotbelongtoconnectionlossofopticalfiber?APermanentopticalfiberconnectionBEmergencyconnectionCFlexibleconnectionDMacrobendingloss第12题Macrobendingiscausedbythenon-uniformityintroducedduringtheproductionprocessofthefiber,unevenpressureduringcabling,anddifferentialthermalexpansionandcontractionofdifferentpartsofthefiberduringusage,resultinginmicron-levelbendingalongthefiber'saxis.第13题Thecorrectstatementis:ATofacilitatethetransmissionoflightwavesinthecore,therefractiveindexofthecladdingmustbeequaltotherefractiveindexofthecore.BTofacilitatethetransmissionoflightwavesinthecore,therefractiveindexofthecladdingmustbegreaterthantherefractiveindexofthecore.Cofacilitatethetransmissionoflightwavesinthecore,therefractiveindexofthecladdingmustbesmallerthantherefractiveindexofthecore.D(a)Tofacilitatethetransmissionoflightwavesinthecore,therefractiveindexofthecladdingmustbegreaterthanthatofthecoatinglayer.第14题TheprinciplebehindconfininglightwithinthecoreofanopticalfiberwithcladdingisARefractionBTotalinternalreflectionattheboundaryofthecladding.CTotalinternalreflectionattheboundarybetweenthecladdingandthecoatinglayer.DReflectionfromtheopticalfiberplasticcoatinglayer.第15题Thegradient-indexfiberutilizestheprincipleoflightscatteringtotransmitlight第16题Therefractiveindexofthegradient-indexfibercoreisgenerallyslightlysmallerthanthatofthecladding.Testing3第1题Themainmaterialusedtomakelight-emittingdiodesisAInsulatorBConductorCSemiconductorDSuperconductor第2题Theessenceofluminescenceisrelatedtothreephysicalprocesses：spontaneousemission,stimulatedabsorption,andstimulatedemission.第3题TheluminescenceofmatterisnotrelatedtotheprocessofelectronenergyleveltransitionASpontaneousradiationBStimulatedabsorptionCStimulatedradiationDSpontaneousabsorption第4题TheFermilevelisthehighestenergyleveloccupiedbyelectronsatroomtemperature.第5题Withoutexternalelectricfield,whatistherelationshipbetweendiffusionmotionanddriftmotionwhenthePNjunctionreachesequilibriumADiffusionmotion>DriftmotionBDiffusionmotion=DriftmotionCDiffusionmotion<DriftmotionDThereisnodirectrelationshipbetweendiffusionmotionanddriftmotion第6题Atthesameexternalelectricfield,thepotentialbarrierofaforward-biasedPNjunctionisgreaterthanthatofareverse-biasedone第7题ThefirstlaserinChinawasborninAChengduOptoelectronicsInstituteBBeijingLaserInstituteCChangchunInstituteofOpticsandMechanicsDShanghaiInstituteofOpticsandMechanics第8题Homogeneousjunctionsemiconductorlasershavetheadvantageoflowlosses第9题ThelaserlightformedbysemiconductorlasersreliesontheamplificationoflightbyASpontaneousradiationBStimulatedradiationCStimulatedabsorptionDPhoton第10题Therearetwomirrorsinarubylaser,oneisatotalmirrorandtheotherisapartialmirror.第11题Whichofthefollowingarelasercharacteristics?AMonochromaticityBCoherenceCNarrowlinewidthDLowbrightness正确答案：ABC第12题Thelighttheincandescentlampemitsismonochromaticlight.第13题Whichofthefollowingnotbelongstoafiberopticamplifier?AEDFABFDFACSOADFRA第14题Opticalamplifierisadevicethatamplifiesanincidentopticalsignalbasedontheprincipleofstimulatedradiationorstimulatedscattering.第15题ALEDradiates2mW,andthedBmvalueofthisradiatedpoweris______.A20dBmB23dBmC3dBmD-20dBm第16题Ann-typesemiconductorhasanumberoffree______.AelectronBphotonsCholesDneutrons第17题RadiationfromanLEDiscausedbytherecombinationof______andelectronsthatareinjectedintothejunctionbyaforwardbiasvoltage.AelectronsBholesCparticlesDphotons第18题Asacarriersource,______hasathresholdcurrent.AanelectronicoscillatorBaLEDCaLDDaconductor第19题ADBRlaserscanbeproducedusingavariationoftheDFBlaserdiode.______controlstheBraggwavelengthbychangingthetemperatureintheBraggregion.AThephasecurrentBThegaincurrentCTheBraggcurrentDThebiascurrent第20题Ap-typesemiconductorhasanumberoffreeholes.()第21题Couplerfeedspowerintotheinformationchannel.()第22题Inopticalfibers,iftherefractiveindexofthecladdingisn2andtherefractiveindexofthecoreisn1,thenn1Testing4第1题Thestructureofaphotomultipliertubedoesnotinclude:APhotocathodeBMultiplicationstagesCPhotonicanodeDCollimator第2题Thestatementthatisincorrectregardingthephotoelectriceffectandsecondaryelectronemissionis:AThephotoelectriceffectisdividedintoexternalandinternalphotoelectriceffects.BUndernormalworkingconditions,moreelectronsareproducedbythephotoelectriceffectthanbysecondaryelectronemission.CTheprinciplesofthephotoelectriceffectandsecondaryelectronemissionarebothbasedontheexcitationofouterelectronsofatoms,causingthemtoovercomethepotentialbarrierandbecomefreeelectronsonthemetalsurface.DTogenerateexternalandinternalphotoelectriceffects,theexcitationenergymustbegreaterthanthemetal'sworkfunction.第3题ThemainfactorsthatdonotcontributetodarkcurrentareAThermalemissionBInter-electrodeleakageCFieldemissionDPhotomultipliertubefatigue第4题Inthefibersystem,theopticwaveisconvertedintoanelectriccurrentbya()().AinformationchannelBopticalamplifiersCphotodetectorDcoupler第5题Atthereceiver,theinformationbeingtransmittedmustbetakenoffthecarrierwave,thisistheprocessof()theopticalsignal.AmodulatingBdemodulatingCemittingDamplifying第6题Photodetectorscanconvertopticalsignalsintoelectricalsignals.Sowhatisthebasicphysicalprincipleinvolvedintheconversionprocess?AComptonEffect

BPhotoelectricEffectCRamanEffectDFaraday

Effect第7题Theanodecharacteristicsofthephotomultipliertuberefertotherelationshipbetweentheanodecurrentandincidentlightflux.第8题Eachphotonscarriesenergywhich

isproportionaltothefrequency

ofthecorrespondingelectromagneticwave.第9题Whyaretheeyesnotsuitableforthelightdetectorofmodernfibercommunications?AItssensitivitytolow-levelsignalsisinadequate.BBreaksanddiscontinuitiescanbeobservedbyviewingthescatteredlight.CResponseistoohigh.DCandothesignalprocessing.第10题photomultipliertubesareinventedbasedon

internal

photoelectriceffect.第11题WhichofthefollowingparametersaretheoperatingcharacteristicsofPINdiodes?ACutoffwavelengthBResponsivityCCurrent-VoltageCharacteristicDNoise正确答案：ABCD第12题WhatisthecorrectstatementaboutPINdiodes?AElectronconcentrationintheregionIismuchhigherthanthatintheregionN.BThereginPandreginNarerelativelythin,andtheregionIisrelativelywide.CThedopingdegreeinregionIisveryhigh.DPINdiodeexhibitsalowresistancestate.第13题Ifadepletionwidthis25umandacarriervelocityis5timestentothepoweroffourmeterspersecond,Whatisthetransmissiontime?A