第1題Whichoneisnotthefunctionofresonator?下列哪項(xiàng)不屬于光學(xué)諧振腔的功能？AFeedbackforstimulatedemission反饋受激輻射BSpatialmodeselection選擇空間模式CMediumActivation激發(fā)介質(zhì)DFrequencyselection選擇頻率第2題Whichonecanhelpwithpopulationinversion?以下哪一項(xiàng)有助于粒子數(shù)狀態(tài)翻轉(zhuǎn)？Aenhancedpumping更強(qiáng)的激勵(lì)抽運(yùn)Bcoolingsystem冷卻系統(tǒng)Cphotonresonating光子諧振DAandB第3題Whichoneisnotthebasicpartofalasersystem?下列哪一項(xiàng)不是激光器的基本組成部分？Apump激勵(lì)源Bresonator諧振腔Cactivemedium工作介質(zhì)DFresnellens菲涅爾棱鏡第4題Whichlaserhasdifferentenergystatefromothers?下列哪種激光具有與其它激光不同的能級(jí)？AHeNe氦氖激光器BDiode二極管激光器CNd:YAGDCO2二氧化碳激光器第1題Whichoneisnotthedifferencebetweenthermalradiationandlaserradiation?ApropagationdirectionBspectrumintensityCradiationsourceDwavelength第2題Whichoneisthespectraldensityofstates?A(8πv^3)/(c^3)B(8πv^2)/(c^3)C(8πv^3)/(3c^3)D(8πv^2)/(3c^3)第3題AccordingtoPlanck’slawofblack-bodyradiation,thewavelengthofmaximumemissiongoeslowerwithrespecttotheincreasingtemperature.Resonators:quiz--作業(yè)第1題Therearefourelementswhicharenecessaryforthelaser,includingPump,Resonator,ActivemediumandLens(Beamshapingelements).第2題Theresonatorbasicallydoesthreethings,notincluding()AFeedbackforstimulatedemissionBDirectionselectionCTransversalmodeselectionDFrequencyselection第3題Inthecaseasthefigureshows,theresonatorcangetfourlongitudinalmodes.Ifwewanttogetasinglemodelaser,oneapproachistoincreasingthefrequencyspacingbydecreasingthecavitylengthL.第4題Inthestabilitydiagram,thepointAstandsforthe().APlaneresonatorBConfocalresonatorCConcentricresonatorLaserrateequations:quiz激光激發(fā)等式：小測(cè)--作業(yè)第1題Therateconstantforspontaneousemission(B)isthesameastherateconstantforstimulatedemission(A).第2題Forthecompetitionofspontaneousemissionandstimulatedemission,whichofthefollowingstatementsiscorrect:AWitheffective“cooling”,wewillhavelowinversion△N=N2-N1BWithlowpumprate,wewillhavehighinversion△N=N2-N1CWithhighphotondensity,stimulatedemissiondominatesevenforlowpopulationinversion第3題Atthelaserthreshold,verysmallchangesofthepumppowerwillresultinsignificantchangesintheproductionofstimulatedphotons.GaussianBeam:quiz--作業(yè)第1題Lasercannotbefocusedtoarbitrarysmallspots第2題Whatistheintensityatthebeamwaist(comparedtothehighestintensityI)?A0BI/eCI/（e^2）DI/(2π)第3題What’sthefactorofSVE?Aexp(-ikz)Bexp(-kz)Cexp(ikz)Dexp(kz)第4題Thesolutionofthescalarwaveequationcandescribethebehaviorbothinthefocusandinthefarfield.BeamParameterProductandBeamQuality:quiz--作業(yè)第1題Hermite-Gaussianmodeshavebothradiusquantizationandangularquantization.第2題TheBBPofareallaserbeamisalwayslargerthantheBBPofaGaussianbeamwiththesamewavelength.第3題Foraspecificlaser,theGaussianbeamcangetsmallerwaistifwechooselenswithhigherdivergenceangle.第4題Fordifferentlasers,ifonehaslargerwaistofGaussianbeam,itshouldhavesmallerdivergenceangle.第5題Thereare4differentlaserswithdifferentwavelengthsλ.Whichonehasthebestquality?Aλ=1μmBλ=800nmCλ=600nmDλ=1.2μmPulsedLaserRadiation脈沖PulsedLaserRadiationIquiz第1題Theshorterwemakethepulsewidth,thesmallerthermalpenetrationdepthwewillget.第2題Foratypicallaserparameters:repetitionrateν=1KHz,pulseenergyE=1mJ,pulseddurationτ=10ns,sotheaveragepowerpm=____,peakpowerp=____;正確答案：:1W正確答案：:100kw第3題Intherateequationsforphotondensity:thesignFΩstandsfor:ApumprateBEinsteincoefficientforstimulatedemissionCinversiondensityDresonatorselectivity第4題Withhigherreflectionandverysmalltransitionresonator,thequalityfactorQoftheresonatorwillbelow.第5題PleaseselectQ-switches:AsaturableabsorbeBpuncheddiskCacousto-opticalmodulator(AOM)Delectro-opticalmodulator(EOM)正確答案：ABCDReflection,absorption,transmission:quiz--作業(yè)第1題Whichapplicationoflaserthefiguremeans?ACuttingBWeldingCHardeningofadrillhole第2題Whathappenedwhenthelaserhitsurfaceofmaterials.（）AReflectionBabsorptionCtransmission正確答案：ABC第3題Therearetwodifferentcomponents(normalcomponentsandparallelcomponents)fortheplanewavesatinterface.LaserMetal-plasmaInteractionⅠ:quiz--作業(yè)第1題Ifω＞ωp,R(w)=1第2題ThewavelengthofNd:YAGlaseris__A10.6μmB1.06μmC0.25μm第3題Whichlaserhasthebestabsorptivity()?ACO2laserBNd:YAGlaserCFiberlaserDKrFlaserLaserMetal-plasmaInteractionⅡ:quiz--作業(yè)第1題Usually,fordistanceslargerthanDebyescreeninglength,thetestchargewouldalmosthavenoinfluenceofthesurroundingcharges.第2題TheDebyescreeninglengthisafunctionofcarrierdensity,andthehighercarrierdensitygetthelargerDebyelength.第3題InlaserinducedplasmaoverasteelworkpieceprocessedwithpulsedCO2laserradiation,whenthelaserintensityI=5x10^7W/cm^2,whichthingmaybenotcorrespondingtoreality.()ACompleteabsorptionofthelaserradiationinsidetheplasmaispossible.BLowabsorptionofthelaserradiationinsidetheplasma.CTheplasmadetachesfromtheworkpiecesometimes.第4題ForLaser-Supported-Combustion(LSC)regime,whichoneiscorrespondingtoreality()AAbsorptioninsidetheplasmaAp≈0BAbsorptioninsidetheworkpieceAT≈0CLaserintensityIsatisfiesIB<I<ID(whereIBisthebreakthrough-thresholdintensity,IDisthethresholdintensityfordetonationwaves)第5題Inthecaseshowedinthefigure,itworksinLSCregimeorbelow.HeatConduction:quiz--作業(yè)第1題Fortheenergyfluxesatsurface,radiativeandconvectivelossescanbenegligibleifAl＜10^3Wcm^(-2)第2題Thetwofiguresshowstheresultsofshortplusesandultrashortpluses,respectively.第3題Theequationisonlysuitableforidealgas.MeltPoolDynamics:quiz--作業(yè)第1題Usually,thesurfacetensionoftheedgeofthemeltpoolislargerthanthatofthecenter.第2題Atthefundamentalsofthemeltflow,thetotalmomentum第3題Usually,formeltpooldynamics,thebalanceequationsformassandmomentuminmostcasescanbesolvedanalytically.Laserbeamsources:quiz--作業(yè)第1題Whatlasersourcesaremainlyusedinmaterialsprocessing?AgasBsolidstateCsemiconductorDpolymer正確答案：ABCAdditivemanufacturing:quiz--作業(yè)第1題WhatarethemainadvantagesofDigitalPhotonicProduction?AlowerweightBlowerenergyC