应用光学41-43.ppt

Chapter4MirrorandPrismSystems,平面镜成像,Opticalsystemscanbeclassifiedintotwotypes:1.symmetrical(对称的),andsphericalsystems2.mirrorandprismsystemsInthepreviouschapterswehavediscussedtheimagingpropertiesoftheaxiallysymmetricalandsphericalsystems,inthischapterwearegoingtodiscussthemirrorandprismsystems.,Anaxially(共轴的)symmetricalsphericalsystemhasmanyadvantagessinceitcontainsasymmetricalaxis（对称轴）.Ontheotherhand,ithassomedisadvantages:thesystemcannotturnbackorreflexsincealloftheopticalelementslocateonacommonline.Thereforethelengthordimension(尺寸)andtheweightofthesystemarecomparativelylarge.,Inordertoovercomethedisadvantagesandreserve（保持）theadvantageswecancombinetheaxiallysymmetricalsystemsandthemirrorandprismsystems.,Questions：,Whycanaddingamirrorandprismsystemintoaaxiallysymmetricalsystemovercomethedisadvantages?Whataretheimagingpropertiesofthemirrorandprismsystems?Howtocombinethemtogether?Howtodesignthemirrorandprismsystems?Thesearewhatwewilldiscussinthischapter.,4.1ApplicationsofMirrorandPrismSystemsinOpticalInstruments,Wecanmakeupvarioussphericalaxiallysymmetricalsystemsbyusinglensestomeetdifferentimagingrequirements.Forexample,atelescopeoramicroscopeisusuallycomposedofseverallenses.,However,theobviousdisadvantageofaxiallysymmetricalsystemisthatthesphericalsurfacescenterofthistypeofsystemmustbelocatedatonecommonline,andusuallythiscannotmeetmanyactualapplications.,Forinstance,asimpletelescopemaybecomposedofapositiveobjectiveandapositiveeyepieceandthiswillbringaninvertedimagewhichisveryinconvenientforobservation.Onthisconditionanuprightlensgroupcanbeaddedintothesystemtogetanerectedimage,asshowninFig.4.1(a).,Thedimensionandweightofthistypeofsystemarecomparativelylargeandmaynotmeettherequirementsoftheopticalinstrumentsusedinmilitary,forexampleshowninFig.4.1(b),containprisms,thuscangetanerected（正立的）imagewithoutaddinganuprightlensgroup,andgreatlydiminish(减小)thedimensionandtheweightoftheinstrument.,Besides,inmanyinstrumentsthelocationandthedirectionoftheaxisusuallyneedtobechangedaccordingtoactualuse,forexample,inatrenchmortar（迫击炮)theaxisofthecollimator(瞄准仪)mayneedtotilt（倾斜）anangleinactualuse,asshowninFig.4.2.,Sometimes,theobserverdoesnotneedtochangehislocationanddirectionwhenobservingenemyssituation,andjustneedstorotatetheprismsormirrors,asshowninFig.4.3.,Fig.4.3,Periscope潜望镜,Generallyspeaking,theusagesofprismsandmirrorsareasfollows:,1）Theycanbeusedtodiminishthedimensionandtheweightofaninstrument.2）Theycanbeusedtochangethedirectionoftheimage,ortomaketheimageinverted.3）Theycanbeusedtochangethelocationandthedirectionoftheaxis,producingacertainperiscope(潜望镜)heightortiltingtheaxisforanangle.4）Withthehelpofrotatingtheprismandmirror,thedirectionoftheaxiscanbechangedcontinuously,enlargingtheobservingfieldofview,4.2imagingpropertiesofmirrors,A,P,O,Q,B,A,Fig.4.4Virtualimageformedbymirror,N,O,I,I,B,4.2.1theimagingpropertiesofsinglemirror,Accordingtoreflectionlaw,thereflectionangleisequaltothatofincidence:,BON=AON=IAOD=AODAD=AD,Conclusion:aplanemirrorcanimageanyobjectpointsideallyinthewholespace.,Propertie1.Theimageandobjectpointsaresymmetricaltothemirror.像与物相对于平面镜来讲是对称的。,Propertie2.Theheightoftheimageisequaltothatoftheobject物像大小一致，且成正象。,中指代表Z轴,P,Q,x,y,z,y,x,z,O,O,大拇指代表X轴,食指代表Y轴,Theimageorientationofamirror:righthandcoordinatesinobjectspace,Righthand,Lefthand,Righthand,Lefthand,Mirrorimage,Righthand,Righthand,Similarimage,Odd(奇)mirrors,Even,奇次镜面反射成镜像；偶次镜面反射成相同的像。,镜像与一致像1）所谓镜像是指若物为右手坐标，像为左手坐标，这种像叫为镜像。,特点：像物同向，左右颠倒(方向相反)，可通过奇次反射得到。2）一致像：物为右手坐标，像也为右手坐标，即物与像是完全一致的，它可通过偶次反射来得到。,Asingleplanemirrorhasthefollowingproperties:,Aplanemirrorcanformanidealimageinthewholespace,andtheimageandobjectpointsaresymmetricaltothemirror.Theheightoftheimageisequaltothatoftheobjectbutdifferentinorientation.,P,P,P1,O1,A2,O2,q,A,A1,A2,-,-,4.2.2theimagingpropertiesoftwomirrors,4.3rotationofmirrors,AOA”=2POP,P,Q,P,Q,O,A,N,N,A,A,2,4.3.1rotationofasinglemirror,Conclusion:,Ifamirrorrotatesanangleofroundanaxisperpendicular(垂直)toincidentplane,theincidentanglechanges,andtheangleofreflectedrayswillchange2.Therotationdirectionoftherayisthesameasthatofthemirror.,-f,Applicationofopticalcomparator(比较仪),graticule分划板,Mirror,Lens,fixedPivot支点,Pole测杆,Pole测杆,x:movingamount,4.3.2Translationeffectofasiglemirror,Q,P,A,A,B,A”,h,2h,Q,P,B,P,AA=2h,O2,O1,q,q,b,P,P,P,A,M,N,I1,I1,I2,I2,90,4.3.3Propertiesoftwomirrors,Conclusion:,Foranyincidentraythatliesinaplane(主截面)perpendiculartothetwomirrors,therotatedangleoftheemergenceraywillbeequaltotwicetheangleofthetwomirrors,regardlessoftheincidentraysdirection。TherotationdirectionwillcoincidewiththatofrotationfromP1toP2accordingtotheorderofreflectionsonthetwo