An Introduction to Practical Laboratory Optics

198 Pages·2014·2.965 MB·English

by  J. F. James

AnIntroductiontoPracticalLaboratoryOptics
Aimed at laboratory workers and students taking laboratory courses in experimental
optics,thisbookintroducesreaderstoopticalinstrumentsandtheiruses.
Thebookexplainsthebasicoperationoflenses,mirrors,telescopesinthelaboratory
andunderfieldconditions,howtouseopticalinstrumentstotheirmaximumpotential
andhowtokeeptheminworkingorder.Itgivesanaccountofthelawsofgeometrical
opticswhichgovernthedesign,layoutandworkingofopticalinstruments.Thebook
describestheinteractionsofpolarizedlightwithmatterandtheinstrumentsanddevices
derivedfromthis,anddiscussesthechoiceofspectrometersanddetectorsforvarious
spectralregions,withparticularattentiontoCCDcameras.
The emphasis throughout is on description, with mathematical precision confined
totheappendices,whichexplaintheraytransfermatrixandoutlinetheSeideltheory
of optical aberrations. The appendices also introduce Fourier methods in optics and
Fouriertransforminfra-redspectrometry.
j.f.james has held teaching positions at The Queen’s University, Belfast, and the
University of Manchester, and is one of the pioneers of Fourier spectroscopy. He is
the author of A Student’s Guide to Fourier Transforms, now in its third edition, and
Spectrograph Design Fundamentals (Cambridge University Press, 2011 and 2007
respectively).

An Introduction to
Practical Laboratory Optics
J. F. JAMES
UniversityPrintingHouse,CambridgeCB28BS,UnitedKingdom
CambridgeUniversityPressispartoftheUniversityofCambridge.
ItfurtherstheUniversity’smissionbydisseminatingknowledgeinthepursuitof
education,learningandresearchatthehighestinternationallevelsofexcellence.
www.cambridge.org
Informationonthistitle:www.cambridge.org/9781107687936
©J.F.James2014
Thispublicationisincopyright.Subjecttostatutoryexception
andtotheprovisionsofrelevantcollectivelicensingagreements,
noreproductionofanypartmaytakeplacewithoutthewritten
permissionofCambridgeUniversityPress.
Firstpublished2014
PrintedintheUnitedKingdombyClays,StIvesplc
AcataloguerecordforthispublicationisavailablefromtheBritishLibrary
LibraryofCongressCataloguinginPublicationdata
James,J.F.(JohnFrancis),author.
Anintroductiontopracticallaboratoryoptics/J.F.James.
pages cm
Includesbibliographicalreferences.
ISBN978-1-107-05054-9(Hardback)–ISBN978-1-107-68793-6(Paperback)
1. Opticalinstruments–Handbooks,manuals,etc. I. Title.
QC371.J362014
681(cid:2).4–dc23 2014014037
ISBN978-1-107-05054-9Hardback
ISBN978-1-107-68793-6Paperback
CambridgeUniversityPresshasnoresponsibilityforthepersistenceoraccuracy
ofURLsforexternalorthird-partyinternetwebsitesreferredtointhispublication,
anddoesnotguaranteethatanycontentonsuchwebsitesis,orwillremain,
accurateorappropriate.
Contents
Preface pageix
1 Introduction:centredopticalsystems 1
1.1 Thecommonpropertiesofopticalinstruments 1
1.2 Opticalelements 1
1.3 Conceptsinopticalinstrumentdesign 3
1.4 Gaussianoptics 11
1.5 Aberrations–aconspectus 13
2 Telescopesandbinoculars 15
2.1 Thevisualtelescope 15
2.2 Galileantelescopes 16
2.3 Keplerianrefractors 17
2.4 Erectingtelescopes 17
2.5 Binoculars 19
2.6 Applicationsoftherefractingtelescope 21
2.7 Reflectingtelescopes 22
2.8 TheNewtoniantelescope 23
2.9 TheCassegraintelescope 23
2.10 Refractorsversusreflectors 26
2.11 Focalreducers 27
2.12 Imagerotators 29
3 Eyepieces,eyesandcolour 30
3.1 Eyepieces 30
3.2 Eyepieceproperties 32
3.3 Astronomicalphotographythroughaneyepiece 35
3.4 Visualobservation 36
vi Contents
3.5 Theeyeasanopticalinstrument 38
3.6 Theperceptionofcolour 39
4 Camerasandcameralenses 43
4.1 Introduction:thephotographiclens 43
4.2 ThedoubleGausslens 44
4.3 Telephotolenses 45
4.4 Wide-anglelenses 45
4.5 Fish-eyelenses 47
4.6 Zoomlenses 49
4.7 Practicalaspects 49
4.8 Architecturalphotography 51
4.9 Schlierenphotography 51
4.10 Theopticaltransferfuncton 54
4.11 TheBoyspointsofalens 55
5 ThescientificCCDcamera 57
5.1 Thetraditionalsilverhalidecamera 57
5.2 Scientificdigitalphotography 60
5.3 Calibration 62
5.4 Radioactivelenses 62
6 Spectrometry 64
6.1 Theprismspectroscope 64
6.2 Thedirectvisionspectroscope 69
6.3 Diffractiongratingspectrometry 70
6.4 Gratingmountings 71
6.5 Concavegratings 76
6.6 Illuminationofaspectrometer 77
6.7 Gratingghosts 80
6.8 Thealignmentofagratingspectrograph 81
7 Interferometersandtheiruses 84
7.1 Interferometry 84
7.2 Oscillation,phaseandphase-difference 84
7.3 Coherence 85
7.4 Divisionofwavefront 86
7.5 Divisionofamplitude 88
7.6 Interferometers 88
7.7 TheFizeauinterferometer 90
7.8 TheMichelsoninterferometer 91
7.9 TheFabry–Pérotétalon 93
Contents vii
7.10 TheMach–Zehnderinterferometer 99
7.11 TheSagnacinterferometer 101
7.12 Finedisplacementmeasurement 102
7.13 Opticalresonators 103
8 Electro-opticaleffectsandtheirpracticaluses 104
8.1 Introduction:polarizedlight 104
8.2 Polarizationeffects 105
8.3 Polarizingelements 108
8.4 Laboratoryusesofpolarizedlight 109
8.5 Faradayeffect 110
8.6 Kerreffect 111
8.7 Pockelseffect 113
8.8 Apracticalexampleofappliedpolarizingeffects 113
9 Microscopesandprojectors 116
9.1 Projectors 116
9.2 TheFresnellens 118
9.3 Microscopes 119
9.4 Köhlerillumination 120
9.5 Travellingmicroscopes 122
10 Siderostatsandcoelostats 124
10.1 Thecelestialsphere 124
10.2 Equatorialtelescopemountings 124
10.3 Coelostats 126
11 Thedetectionandmeasurementofradiation 130
11.1 Thegeometryofradiationmeasurement 130
11.2 Thedetectionofradiation 132
11.3 Theclassificationofradiationdetectors 133
11.4 Thefarinfra-red 133
11.5 Themiddleinfra-red 134
11.6 TheUVOIRregion 134
11.7 Thefarultra-violet 136
11.8 Typesofspectra 137
11.9 Blackbodyradiation 138
12 Practicalities 141
12.1 Cleaningopticalsurfaces 141
12.2 Mountingopticalparts 144
12.3 Opticalfilters 145
viii Contents
AppendixA Gaussianoptics 149
AppendixB Opticalaberrations 162
AppendixC AbriefintroductiontoFourieroptics 174
Furtherreading 181
Index 183
Preface
Themostfamousandillustriousmis-userofanopticalinstrumentisSherlock
Holmes.ThereisaniconicfigureofhimwithInvernesscape,deerstalkerhat
andcalabashpipe,peeringthoughamagnifyingglass,thelatterheldatarm’s
length,toinspectapossiblebloodstain.
Thisisthewrongwaytouseamagnifyingglass–whichincidentallyshould
always have a plano-convex lens rather than the biconvex lens with which
manycheapversionsareprovided.Theglassshouldbeheldclosetotheeye,
planesidefacing,andtheobjectbroughtinuntilitisinclearfocusatacom-
fortable distance for viewing. This gives the clearest image, the widest field
andtheminimumofopticalaberrations.Itistheattentiontosmalldetaillike
this which helps ensure success. Watchmakers do it properly, with a loupe, a
lensheld,likeamonocle,intheeyesocket.
In experimental science, especially in physics laboratories, it is sometimes
found,whenbeginninganewpieceofbasicresearch,thatnoappropriateappa-
ratus exists and that it is necessary to improvise. The traditional laboratory
stand-and-clamp then comes into its own, followed, after some experimenta-
tion,byaproperlydesignedsystemwithanopticalbenchortablewithlenses,
mirrors and other basic optical elements for measuring and analysing radia-
tion.Skillsinthedesignandassemblyofsuchprovisionaldevicesarepartof
thetrueexperimenter’sart.
In any field of science, a large part of experimentation involves light, be
itphotography,photometry,polarimetry,microscopyorspectroscopy,andthe
proper selection and application of optical elements and devices may have a
great effect on the satisfactory outcome of experimental work. Much can be
donewithstandard,versatile‘common-user’instrumentssuchascamerasand
microscopes, but all too often there is a particular measurement to be made
whereapparatusmustbedesignedandconstructedbeforetheexperimentcan
bedone.