光学工程考研英语面试

1．光的干涉(Interferenceoflight):若干个光波相遇时产生的光强分布不等于由各个成员波单独造成的光强分布之和，而出现明暗相间的现象。Anumberoflightwavesmeet,thelightintensitydistribution（强度分布）isnotequaltoseparatecausedbythevariousmembersofthewaveintensitydistributionandtheemergence（出现）ofthephenomenonoflightanddark.相干条件：只有两列光波的频率相同，相位差恒定，振动方向相同的相干光，才能产生光的干涉。Coherence[kəu'hiərəns]conditions：Onlytwolightwavefrequency（频率）,thephase（相位差）constant（恒定）,thedirectionofvibration（振动方向）ofthesamecoherentlight（相干光）inordertoproducetheinterferenceoflight.（干涉）由两个普通独立光源发出的光，不可能具有相同的频率，更不可能存在固定的相差，因此，不能产生干涉现象。Thelightemittedbythetwoordinaryindependentlightsources,cannothavethesamefrequency,thelesslikelythereisafixed（固定的）phasedifference,therefore,cannotproduceinterference.2．光的衍射(Thediffractionoflight)：光绕过障碍物偏离直线传播路径而进入阴影区里的现象，叫光的衍射。Lightaroundobstaclestodeviatefrom（偏离）astraightlinepathintotheshadowzonephenomenon,calledthediffractionoflight.光的衍射和光的干涉一样证明了光具有波动性。包括：单缝衍射、圆孔衍射、圆板衍射及泊松亮斑Lightdiffraction（光的衍射）andinterferenceoflighasthat（一样、证明了）thelightwiththevolatility（波动性）.Include:single-slitdiffraction,circularaperturediffraction,diffractionofthecircularplateandthePoissonbrightspot.3．光的色散(Dispersionoflight)指的是复色光分解为单色光的现象Itisthephenomenonofthepolychromaticlightisdecomposed/breakup/resolveintomonochromatic.[,mɔnəukrəu'mætik]（单色的：singlecolour）.Multicolor['mʌlti,kʌlə]:多色的在光学中，对于不同的波长，有不同的介质折射率n(λ)，当白光通过三棱镜后，由于棱镜对各种颜色光的偏折程度不同，从而在空间上被分离的现象。Fordifferentwavelengthsshowsdifferentrefractiveindexn(λ)intheopticalmedium，whenwhitelightthroughaprism(棱镜),duetoPrismdeflectiononavarietyofcolorsoflightinvaryingdegrees,resultinginspatialseparation第2页共4页phenomenon.一般波长越小，折射率越大；紫色光折射率大，红色光折射率小。Generalthesmallerthewavelength,therefractiveindexofthegreater；Thepurplelightrefractiveindexgreaterthantherefractiveindexoftheredlight.4.光的折反射①反射(Thereflectionoflight)：一种光学现象，指光在传播到不同物质时，在分界面上改变传播方向又返回原来物质中的现象。Anopticalphenomenon,thelightspreadtodifferentsubstancestochangethedirectionofpropagation/transmissionintheboundarysurfacereturnedtotheoriginalphysicalphenomenon.②折射(Refraction[ri'frækʃən]oflight)：光从一种透明介质斜射入另一种透明介质时，传播方向发生偏折，这种现象叫光的折射Lightslanting（斜射）fromatransparentmediumintoanothertransparentmedium,thepropagationdirectionappearsdeflection,thisphenomenoniscalledrefractionoflight.不同之处：光的折射与光的反射一样都是发生在两种介质的交界处，只是反射光返回原介质中，而折射光则进入到另一种介质中。注意：在两种介质的交界处，既发生折射，同时也发生反射。反射光光速与入射光相同，折射光光速与入射光不同。Lightrefractionandreflectionoflightarealsoappearinthejointoftwomedia,butthereflectedlightreturnstotheoriginalmedium,therefractionoflightintoanothermedium.Note:atthejointofthetwomedia,bothrefraction,butalsoreflected.Reflectedlightandtheincidentlightatthespeedoflight,refractionoflightspeedisdifferentwithincidentlight.5.光的偏振(Polarizationoflight)①线偏振光②圆偏振光③椭圆偏振光④部分偏振光⑤非偏振光（自然光）①Linearlypolarizedlight②Circularlypolarizedlight③ellipticallypolarizedlight④partiallypolarizedlight⑤Naturallight光的偏振（polarizationoflight）振动方向在垂直于传播方向规律性变化的现象。它是横波区别于其他纵波的一个最明显的标志。光波电矢量振动的空间分布对于光的传播方向失去对称性的现象叫做光的偏振。只有横波才能产生偏振现象，故光的偏振是光的波动性的又一例证。Thephenomenonofvibration（振动/shake）directionperpendicular（垂直）tothepropagationdirectionchangedregularly.第3页共4页Itisoneofthemostobvioussignoftheshearwaveisdifferentfromotherlongitudinalwave.Lightwaveelectricvectorvibrationofthespatialdistributionofthedirectionofpropagationoflightlostsymmetry（对称）ofthephenomenoniscalledpolarizationoflight.Onlytransversewavescanproduceapolarizationphenomenon,sothepolarizationoflightisanotherexampleofthewavenatureoflight.6.光电效应（Photoelectriceffect）当光照射到物体上使物体发射电子或电导率发生变化或产生电动势等改变了物体电学特性的现象称为光电效应。WhenlightshinesontheobjectsothatobjectsemitelectronsorconductivitychangeorgeneratesanelectromotiveforcetochangetheobjectoftheelectricalpropertiesofthephenomenonknownasPhotoelectriceffect.Photoelectriceffectcandivideintotheexternalphotoelectriceffectandtheinternalphotoelectriceffect.Whenthephenomenonisproducedinsurface,itiscalledexternalphotoelectriceffect,whenithappensinside,wecallitinternalphotoelectric!TheinternalphotoelectriceffectincludesPhotovoltaiceffectandPhotoconductiveeffect.7.空间频率和时间频率（Spatialfrequencyandtimefrequency）所谓空间频率是指在一定方向上的单位空间（距离）波动的周期数。它不仅具有大小而且具有方向是一个矢量。Theso-calledspatialfrequencyinacertaindirectionandunitspace(distance)fluctuations（波动）inthenumberofcyclesthatitnotonlyhasthesizeanddirectionofavector.频率，是单位时间内完成振动的次数。Frequencyisthenumberofvibrations（振动）perunittimetocomplete8.粒子数反转粒子数反转（populationinversion）是激光产生的前提。用某种方法使处在高能级上的原子数多于处在低能级上的原子数，而且这种状态能够维持下来。PopulationInversionisthepremiseofthelaser.ItisaphenomenonthatInsomewayinthenumberofatomsontheenergylevelthanthenumberofatomsinalowenergylevel,andthisstatecanbemaintaineddown.9.波粒二象性(Wave-particleduality)是指某物质同时具备波的特质及粒子的特质Itisreferredthatasubstanceatthesametimewiththewavecharacteristics第4页共4页andparticlecharacteristics.10.倏逝波（隐失波evanescent[,i:və'nesənt]wave）在全反射时，大部分光会直接反射，而一小部分光会进入分界面，并传播一小段距离，然后反射出去，这种表现出特殊性质的波称为倏逝波Whenthetotalreflection,mostofthelightdirectlyreflectedasmallportionoflightwillentertheinterface,andspreadashortdistance,andthenreflectedoff.Thisshowthespecialnatureofthewaveknownas~11.散射(scattering['skætəriŋ])散射是由于媒质不均匀所致，辐射在