光的干涉應(yīng)用舉例課件

光的干涉應(yīng)用舉例簡要回顧王涉條件(充分條件;必要條件)相干和不相王相干光源與不相干光源楊氏雙縫干涉薄膜干涉(等傾干涉、等厚干涉)Lightbeamscaninterferewitheachother:TwopointsourcesDifferentseparationsnotethedifferentpatternsConstructivevs.destructiveinterferenceConstructivevsdestructiveinterferenceCoherentvsincoherentinterference相長WavesthatcombineConstructiveinphaseadduptointerferenceelativelyhighirradiance(coherent)相消Wavesthatcombine180°∧Destructiveoutofphasecanceloutnterferenceandyieldzeroirradiancecoherent)WavesthatcombinewithlotsofdifferentphasesIncoherentnearlycanceloutandadditionyieldverylowirradiance不相干CoherentvsIncoherentLightLaser相干光源不相干光源CoherentlighthtIt'sstrongcoherentlg2.tsdirection1.It'srelativelyw2.Itsomni-direct3.Totalirradianceon2oro3.Totalirradiance∝N4.Totalirradianceisthemag-squareofthesumofindividualfields4.Totalirradianceisthesumofmag-squareofthesumofnaiviaualirradiancesndividualfieldstotal=E,+EEl,+12+…,+Youngsdouble-slitinterferenceYoungsENarrowshinObservingscparticlethePettenobservedonscreebwn重測(cè)定波長測(cè)定折射率等傾干涉等傾干涉是指厚度相等的薄膜所發(fā)生的干原涉。同一級(jí)條紋對(duì)應(yīng)著同一傾角d=n,(AB+BC)-n,AOd=2n,docos,-22do√(2-mn2sin2i)干涉相長亮點(diǎn)(2j+1)千涉相消暗點(diǎn)(2+1)相長(亮點(diǎn))nsin=0,1,2,…)(1-35)或者2dn2cosi2相消(暗點(diǎn))等厚干涉等厚干涉是厚度不同的薄膜所發(fā)生的干涉。同一級(jí)條紋對(duì)應(yīng)著同一厚度。d=n2(AB+BC-nCD之δ=2d0√(n2SIn2λ2SnoO(2j+1)干涉相長亮紋2d2}2干涉相消暗紋(其中廣=0,,2,3A)等傾與等厚干涉的區(qū)別類別項(xiàng)目等傾等厚光源面光源點(diǎn)光源條紋形狀內(nèi)疏外密的同心圓環(huán)等間距直線狀干涉級(jí)內(nèi)高外低高高低低對(duì)光學(xué)表面干涉濾光片磨光的檢驗(yàn)光的