17p4周六和周日晚深外ap物理第3次課optics

APPhysics2:LectureD&LGeometricElectromagnetic電磁波譜頻率從高到低的順序需記住Reflectionand法入射 反射折射光/透射Snell’sSnell’sIndexofrefraction折射cv:wavelengthoflightinaApparent水下物體看起來(lái)比實(shí)際要Dispersion色三棱鏡光線向底面偏色散的原因:不同波長(zhǎng)(頻率)的光折射率不對(duì)于一般玻璃,紫光折射率大,紅光折射率Criticalangle臨界角n1>n2入射介質(zhì)的折射率大于折射介質(zhì)的折射fiberoptic(例如從玻璃射向空氣fiberopticθ1>θcwhereθcsin–1(n2/n1入射角大于臨界SpecularandDiffuseReflectionatadefiniteanglefromaverysmoothsurfaceiscalledspecularreflection鏡面反射scatteredreflectionfromaroughsurfacene等大正立(upright虛像(virtualConcave/ConvexConcavemirror凹面FFocusConvexmirrorFFocus

f:focallengthaxis:Rradiusofcurvatureaxis:Mirror光路圖畫(huà)(1)平行于主光軸光線反射過(guò)焦(2)過(guò)焦點(diǎn)光線反射光平行于主光(3)過(guò)光心光線以主光軸以上三選二即可確定Converging/DivergingConvergingLens凸透DivergingLens凹透Lens光路圖畫(huà)(1)平行于主光軸光線過(guò)焦(2)過(guò)光心光線不偏ObjectImageRelationship面鏡透鏡都適用f焦So(物距 為Si(像距實(shí)為正虛為f(焦距匯聚為正發(fā)散為

So:物

Si像(即凸透鏡和凹面鏡為正,凹透鏡和凸面鏡為負(fù)放大倍數(shù)m=-Si/So(m>0像為正立 成像計(jì)算例Converginglens,So=Convexmirror,So= (1等大倒立(2縮小正立Spherical&Chromaticaberration(APAberration像差:光線沒(méi)有準(zhǔn)確在焦點(diǎn)處匯紫邊原因紫邊原因chromatic PhysicalElectromagnetic電磁波譜頻率從高到低的順序需記住ElectromagneticWave(AP 從E指向B,大拇指為 衍射是指波遇 物時(shí)偏離原來(lái)直 的物理現(xiàn)洞越小,衍射現(xiàn)象最明Huygen’s 原 弱P強(qiáng)P強(qiáng)強(qiáng)destructiveinterference,與該點(diǎn)距離兩個(gè)點(diǎn)源的pathdifference(波程差也就PP點(diǎn)ΔL=L2L1interferenceofYoung’sdouble–slitexperiment(1800年明暗相間的條紋(brightanddark亮帶/暗帶出現(xiàn)的位置Diffractionand計(jì)較準(zhǔn) θθ小角小角度近單色光與白光的雙縫衍條紋間距和波長(zhǎng)(顏色)有波長(zhǎng)越大紅光vs藍(lán)光的條紋白光 條紋

衍射光柵會(huì)形成非Sharp的條Single-SlitGeometricoptic認(rèn)為光沿直實(shí)際上狹縫很細(xì)的時(shí)候,屏幕上會(huì)有衍射條紋出光的衍射現(xiàn)的邊緣是模糊Single-SlitDiffraction的計(jì)算(APDarkfringesinsingle-slit注意 計(jì)算的是暗帶的位置ThinFilmInterference薄Phase光從折射率小的介質(zhì)射向折射率大的介質(zhì)反射光有halfcyclephase光從折射率大的介質(zhì)射向折射率小的介質(zhì),反射光沒(méi)有phaseThinFilm在左邊面反射的光(Ray1halfcyclephase在右邊面反射的光(Ray2)nophaseThinFilm當(dāng)d=λ/43λ/4…時(shí)Ray1和Ray2的光程差ΔL2dλ/2再加上phasechange所帶來(lái)的半個(gè)波長(zhǎng)的差異Ray1正好差整數(shù)倍的波因此在特定的厚度處,兩束反射光會(huì)發(fā)生constructive因此肥皂膜上會(huì)形成不同顏色的光波長(zhǎng)不同,故其反射光 Color 情況一n1nfilmRay1有phaseRay2無(wú)phase2dm1/2λfilm時(shí)發(fā)color

nfilm>Color 情況二n1nfilmRay1有phaseRay2有phase當(dāng)2d=mλfilm時(shí),發(fā)生color

nfilm<Newton’s質(zhì)量差 屏幕有”油花”,就 Thin-FilmInterference的應(yīng)檢測(cè)材料是否有缺偏Transverseand振動(dòng)方向 方向垂振動(dòng)方向 方向一Waveonastring間插入一個(gè)斜著放的偏振片,眼鏡原光non-反射光AntiglarepolarizingLens:只允許垂直分量通波動(dòng)的性質(zhì)總Diffraction,interference,refraction,reflection橫波和縱波都有Polarization只有橫波才有,縱波沒(méi)Onlywavesexhibitinterferenceand能否觀測(cè)到衍射 現(xiàn)象,常被用于證明某種物質(zhì)是不是波More a.Assuminganindexofrefractionof1.00forair,usethegraphtodetermineavaluefortheindexofrefractionoftheglassfortheredlight.Ex inhowyouobtainedthisvalue.b.Forthisredlight,determinethei.Thefrequencyinii.Thespeediniii.Thewavelengthin Theindexofrefractionofthisglassis1.66forvioletlight,whichhaswavelength425nminair.i.Giventhesame angle1,showontheraydiagramonthepreviouspagehowtherefractedrayforthevioletlightwouldvaryfromtherefractedrayalreadydrawnfortheredlight.ii.Sketchthegraphofsin2versussin1forthevioletlightonthefigureonthepreviouspagethatshowsthesamegraphalre