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Physics 134 Optics Laboratory Spring 2018 $& %& & 0 6%& 5 6$& % 59.:+ & . 7488*+, 6 % 0E/B;18.,?;<."=A*’.;58>;.B?.A.@./.FA.*;+.A+.*/=BG/6%BHC.;*88>411..DD..;88&>.1I$.6.’C*84 J4*EE,K,*().L;=M*+.N.4(*.+);(:;8:.:*L,;),4( ! ’5;B. ?.!9%O".N.&9&&#../&9& P1 " ;.... ?.Q92 &*6&!.N.!9*6&2../&9&"2P1 1 0 BC*84?.&9&%$22$$.N. 9*6&O../" .RR51 -./ # ’C*84?.6&9&&#O.N.&9&&&2../$#P1 (+,) $ $ ?.%%9!../&9222.R*8.S4T1 ’()* % !U ?.&9!O & 2 %& %$ %" % %2 34+,),4(./551 SemesterCalendar The notation “1–1” indicates the first experiment of the semester, and the first week of three weeks spent on that experiment. “3–2” means the third experiment of the semester, and the secondofthreeweeksspentonthatexperiment. Meeting Week Thursday Friday 1 Mon,Jan15toFri,Jan19 1-1 1-1 2 Mon,Jan22toFri,Jan26 1-2 1-2 3 Mon,Jan29toFri,Feb2 1-3 1-3 4 Mon,Feb5toFri,Feb9 2-1 2-1 5 Mon,Feb12toFri,Feb16 2-2 2-2 6 Mon,Feb19toFri,Feb23 2-3 2-3 7 Mon,Feb26toFri,Mar2 3-1 3-1 8 Mon,Mar5toFri,Mar9 3-2 3-2 9 Mon,Mar12toFri,Mar16 SpringBreak 10 Mon,Mar19toFri,Mar23 3-3 3-3 11 Mon,Mar26toFri,Mar30 TR-1 TR-1* 12 Mon,Apr2toFri,Apr6 TR-2 TR-2 13 Mon,Apr9toFri,Apr13 TR-3 TR-3 14 Mon,Apr16toFri,Apr20 TR-4 TR-4 15 Mon,Apr23toFri,Apr27 Reportsdue *Becausethismeetingwouldoccuronaschoolholiday(CésarChávezDay),thismeetingshould berescheduledindividuallywithProf.Saeta. Summary reports are due by17:00twodaysbeforethefirstlabmeetingforthenextexperi- ment. The60-minutefinalexamwillbegivenonFriday,May4at1:30PM. Physics 134 ii Introduction Thislaboratory/lecturecourseisdesignedto 1. reinforceandextendyourskillsindesigninganexperimenttotestahypothesis,andtofine- tuneyourexpertiseinrigorouslyanalyzingtheresultsofyourmeasurementstodetermineif thehypothesishasbeendisprovedorsupportedbyyourexperimentalstudies; 2. extendyourknowledgeoftheoreticalopticsandintroducenewexperimentaltechniquesin optics; 3. engageyouinperforminginterestingandchallengingexperimentsinoptics,piqueyourin- terestinexperimentalphysics,andinspireyoutopursueacareerinscience. The course consists of 3 laboratory experiments, one technical report project, and roughly 15 lectureswithtwoassociatedproblemsets.Thereisalsoa60-minutefinalexam.Theexperiments aretobechosenfromeightpossibleexperimentsthatarecurrentlysetupinthelaboratory.The lectureswillbegivenduringthefirsthalfofthesemester,at10AMonMonday,Wednesday,and Fridayofeachweek. Thefirstlabmeetingwillbeaworkingsession! Itisimportantthatyou readthelabmanualandindicatetoyourinstructorbyemailwhichexperimentyouwouldlike toperformfirst. Ascheduleoflabmeetingsappearsonpageii. Threelaboratorymeetingsareallottedforeach of the experiments. The lab instructions leave a good deal of room for your own creativity, so you will need to think carefully about each experiment before coming to lab. References are giveninthelaboratoryinstructionstobackgroundreadingmaterialwhichcanbefoundinthe mainlaboratory,JacobsB121. Youareencouragedtobrowsethroughthebooksandreadthem inthelab,butpleasedonotremovethesebooksfromthelab! Ifyouphotocopythesectionsor chaptersofinterest,wecanallsharethebooksharmoniously. Animportantlessoninworkingeffectivelyinalaboratoryistoarrivewell-prepared. Toencour- age you to do this, we are requiring reading logs. That is, by noon of the day of the first lab meetingforeachexperiment,youmustsendyourinstructorsemaildemonstratingthatyouun- derstandthemainpointoftheexperiment. Inaddition,youshouldincludeanyquestionsthat havealreadyoccurredtoyou. Atthediscretionofyourinstructor,theremaybeadditionalread- inglogsrequiredforlaterdaysintheexperiment. Laboratory notebooks are an important part of this lab course and will be primarily a diary of what you do in the laboratory; they should also include an informal summary of results, data analysis,andconclusionsattheendofeachweek’swork.Attheendofeachexperiment,aformal summarywithdataplots,measuredvalueswithuncertainties,andanyfinalinsightsshouldbe preparedusingReVTEX. SupportfilesareavailableonSakaiintheWritingfolder. Thesereports aretypically7–10pageslong. ThesourcefileandapdfversionshouldbesubmittedonSakai, andahardcopyshouldaccompanythelabnotebookforgradingandfeedback.Theseelectronic “summaryreports”willbearchivedandsharedwithfuturestudentswhoarepursuingtopicsthat overlapwithyourwork. Summaryreportsofanexperimentareduetwodaysbeforethefirstlab iii Physics 134 meetingofthenextexperiment, sothatyouwillhavetimetoprepareforthenextexperiment. Thatis,theThursdaysectionwillsubmitnotebooksonTuesdayby17:00,andtheFridaysection willsubmitnotebooksonWednesdayby17:00;seethecalendaronpageii. Therewillbeamultiplechoicefinalexaminationgivenattheendofthesemester.Questionson theexamwillcoverthematerialinthelectures,problemsets,andallexperimentssetupinthe laboratory. However,theexamwillbegradedsothatyoucanobtainascoreof100evenifyou choosenottoanswerthequestionspertainingtotheexperimentsthatyouhavenotperformed. Thegradesonthethreesummaryreports,thetechnicalreport,andthecombinedgradesinthe homework, readinglogs, andfinalexamwillbeequallyweighted(1/5each)toderivethefinal gradeinthecourse. Asageneralrule,thegradeforalatenotebookwriteupwillbereduced basedonhowlatetheworkissubmitted. Exceptionswillofcoursebemadeforillness,natural disasters,orsimilarunusualcircumstances. Pleasebesuretoappriseyourinstructorofpoten- tiallyextenuatingcircumstances. Thiscoursecarriestwounitsofacademiccredit,andhenceyoushouldbedevotinganaverage of6hours/week(absolutemaximumaverageof8hours/week)tothecourse.Thisfigureincludes the3-hourlabsessionand1.5hoursoflecture(averagedoverthesemester)eachweek. Ifyou findthatyoumustspendmoretimethanthistocompletetheworktoyoursatisfaction,please notify your instructor. We intend this course to pique your curiosity and provide an outlet for your creativity, not to beat you senseless with a heavy load of required work. If you enjoy this courseasmuchastheinstructorsdo,itwillbeahighpointofyoursemester. Physics 134 iv Contents Calendar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii LabReports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii Graphs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi 1 FraunhoferandFresnelDiffraction 1 1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 CircularAperture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.3 FresnelDiffractionbyaStraightEdge. . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.3.1 Recording2-DDiffractionPatternswithaCCDCamera . . . . . . . . . . . 6 2 GratingSpectrometer 7 2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.2 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.3 HydrogenorSolarSpectrum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.3.1 TheBalmerSeriesofHydrogen. . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.3.2 TheSolarSpectrum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.4 NaDoubletandCollision-BroadenedHg . . . . . . . . . . . . . . . . . . . . . . . . 14 2.4.1 TheSodiumDoublet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.4.2 TheMercuryLineWidth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.5 AppendixtoExperiment2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.5.1 TheSPEX500MScanningGratingSpectrometer . . . . . . . . . . . . . . . 14 2.6 ControllingtheSPEXSpectrometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2.6.1 RecommendedStartupProcedure . . . . . . . . . . . . . . . . . . . . . . . . 19 2.6.2 TakingSpectra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 2.6.3 WherearetheData? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 2.6.4 RemakingaPlot. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2.6.5 WorkingonAnotherComputer. . . . . . . . . . . . . . . . . . . . . . . . . . 22 2.6.6 CalibrationLines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 3 ScanningFabry-PerotInterferometer 25 3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 3.2 HeNeLaser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 v Physics 134 Contents Contents 3.2.1 MeasuringtheModeSeparation . . . . . . . . . . . . . . . . . . . . . . . . . 31 3.2.2 MeasuringtheWidthoftheDopplerEnvelope . . . . . . . . . . . . . . . . 32 3.2.3 MeasuringtheWidthoftheLambDip . . . . . . . . . . . . . . . . . . . . . 32 3.2.4 Polarization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 3.3 MeasuringtheZeemanSplittingofNeon . . . . . . . . . . . . . . . . . . . . . . . . 33 3.3.1 MoreAdvancedMeasurements . . . . . . . . . . . . . . . . . . . . . . . . . 36 4 MichelsonInterferometer 39 4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 4.2 White-LightFringes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 4.2.1 GroupIndex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 4.3 HeNeWavelength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 4.4 IndexofAir . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 4.5 RecordingFringes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 5 FourierTransformSpectroscopy 49 5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 5.2 SodiumDoublet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 5.3 HgGreenLine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 6 QuantumOptics 55 6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 6.2 TheQuantumNatureofLight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 6.2.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 6.2.2 DemonstratingtheQuantumNatureofLight . . . . . . . . . . . . . . . . . 59 6.2.3 TheExperimentalSetup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 6.2.4 MeasurementsDuringtheFirstLabMeeting. . . . . . . . . . . . . . . . . . 66 6.2.5 TestingtheQuantumNatureofLight . . . . . . . . . . . . . . . . . . . . . . 68 6.3 TestsofBell’sInequality. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 6.3.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 6.3.2 TheExperimentalSetup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 6.3.3 PerformingTestsofBell’sInequality . . . . . . . . . . . . . . . . . . . . . . . 72 6.4 QuantumEraser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 6.4.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 6.4.2 TheExperimentalSetup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 6.4.3 NextSteps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 7 GeometricalOptics 83 7.1 FocalLength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 7.2 RayTracing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 7.3 AligningOptics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 7.3.1 ImageCaptureSoftware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 7.3.2 MATLABImageToolbox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 7.3.3 SpecificationsforyourCamera . . . . . . . . . . . . . . . . . . . . . . . . . . 89 Physics 134 vi Contents Contents 7.4 Notesontheapparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 7.4.1 TheOpticalRailandtheThinLensEquation . . . . . . . . . . . . . . . . . 89 7.4.2 PreliminaryExploration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 7.4.3 QuantitativeMeasurements . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 7.4.4 Hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 7.5 Warmupexercisestodoifyouwish . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 8 FresnelCoefficients 93 8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 8.2 TheoreticalBackground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 8.2.1 Snel’sLaw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 8.2.2 LawofMalus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 8.2.3 FresnelCoefficients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 8.2.4 Brewster’sAngle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 8.2.5 TotalInternalReflection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 8.2.6 WaveplatesandCircularPolarization . . . . . . . . . . . . . . . . . . . . . . 97 8.3 ExperimentalSetup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 8.4 QualitativeMeasurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 8.5 QuantitativeMeasurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 8.6 AppendixA:AlignmentSuggestions . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 8.7 AppendixB:SampleDataforFresnelCoefficients . . . . . . . . . . . . . . . . . . . 101 A DataAnalysisUsingIgorPro 103 B DataAnalysisUsingMATLAB 111 C DataAnalysisUsingOrigin 115 vii Physics 134 Reports Introduction LabReportsasScientificPapers YourlabreportsforPhysics134maybequitedifferentfromtheshortlabsummariesyouhave prepared for other courses. A Physics 134 report should be in the style of a scientific research publication: a self-contained exposition of the question, the approach you took to answering it, andtheresultsyouobtained. Thereportshouldbeunderstandableandconvincingto, let’s say,afuturejuniorphysicsmajor,withoutreferencetoeitherthelabmanualoryourlabnote- book. Yourlabreportisbothascientificinvestigationandapieceofwriting,sogoodwritingis important. YourreportshouldrespecttheconventionsdescribedintheAmericanInstituteofPhysics“Guide for Metric Practice,” which is available on the department website at writing. Please write in LATEXusingthedocumentclassrevtex4-1touseRevTeX4.1,thestandardforsubmissiontoAPS andAIPjournals. SeetheDepartmentLATEXpageformoreinformationongettingstartedwith LATEXandforusingRevTeX. Suggestionsforwritingthereport • Rememberyouraudience,andmakesureyourpaperisclearandcompellingtoareader who is unfamiliar with the Physics 134 experiments. You might ask a friend who isn’t in Physics134toreadyourdraftandtellyouwhattheythinktheylearnedfromit. • Theheartofaphysicspaperisthegraph(orgraphs)thatsummarizeyourprincipalresults. Everythingthatappearsinyourpaperbeforethisfigureleadsuptothefigure,andevery- thingthatappearsafteritdiscussesitssignificance. Toleaduptoyourcentralfigure,you mustmotivateyourinvestigation(answerthe“sowhat?” question),explaintheapproach youtookinyourinvestigation,andexplainyoursetupandprocedureinenoughdetailto clearlydefineallthedatashowninthefigure. Todiscussthesignificanceofyourcentral figure,youmustexplainthelogicalortheoreticalbasisforyourinterpretationofthefigure, interpretthefigure(includinguncertainties!) fairly, andsuggestpossibleextensionsand applicationsofyourwork. • Refertothespecificcontentguidelinesonthenextpage. • Examinepastlabreportsorsamplescientificarticles,payingattentiontostyleandformat choices. For example, all figures should have figure numbers and informative captions. Figuresshould“float”tothetoporbottomofapage,andshouldthereforebereferenced inatleastoneappropriateplaceinthemainbodyofthepaperbynumber, notposition. Thatis,donotreferencethe“figurebelow,”sinceitspositionmayshiftduringtypesetting. Numberedin-textcitationsshouldrefertoentriesinalater“References”section. • Yourlabreportshouldbeself-contained, sothatareadercanfinditclearandconvincing withoutreferringtomaterialthatisonlycontainedinthelabmanualoryourlabnotebook. Physics 134 viii Introduction Reports • ReportsshouldbesubmittedtoyourSakaidropbox,bothinsourceandpdfformat. Pre- pareafolderforeachreport,andplacefiguresandsourcefiles(.texor.ltx)inthefolder. • The scientific community and funding agencies place increasing importance on data archiving. In that spirit, you should upload your data to the same drob box folder that contains the corresponding report, in the format(s) you employ (typically spreadsheets andIgorexperimentfiles). Specificcontentguidelines Exceptforthetitleandabstract,thesearemerelyguidelinesfortheinformationyourreport shouldcontain,NOTrequirementsorevensuggestionsforsectionheadingswithinyourre- port. Organizethemainbodyofyourreportinanywaythattellsthestoryofyourinvestiga- tionclearlyandlogically. Title Yourreportshouldbeginwithatitle. Abstract Next comes a 2–5-sentence abstract saying what you set out to measure/investigate, whatmethodyouused,andwhatresultsyoufound. Thisissomethinglikethethumbnail versionoftherestofyourreport. Aftertheabstract, startthetextofthereportitself; the mainbodyshouldnotreferbacktotheabstract. Introduction/Motivation • Whatquestionareyouinvestigating? Donotassumethatthereaderisfamiliarwith Physics134experimentsalready,sobesuretogivesomecontext. • Whyisthisinvestigationinteresting? (forexample,illustrationofanimportantprin- ciple? relationshiptoatechnology? Discrepanciesthatmanygroupshaveseenand youcanexplain?Particularchallenge?Other?) • What if any expectations and/or hypotheses did you have as you started the data- taking?Why? TheoryandMethods • Writethisforareaderwhodoesnotknowwhatyoudidinlaborwhatequipmentyou had available to you. This should be a logical exposition of what you did to obtain thefinalresult, andwhy eachstepwasimportantorrelevant. Attentiontodetailis important. • Makesureallsymbolsaredefinedattheirfirstuse;useacronymssparingly. • Carefullylabeleddrawingsareveryhelpful.Theseshouldbereferencesfromthetext byFig.#andpushedtoeitherthetoporbottomofthepage. ix Physics 134 Reports Introduction • Considerpresentingsometheoreticalbackgroundforyourinvestigation. Youneed notshoweachstepofaderivation,butthestartingpoints(includingapproximations andassumptions)shouldbeclearlysetup,andthefinalresultshouldbeprominently reported. Results/Discussion • Makesurequantitiesarewelldefined.Unitsanderrorsarealsoimportant. • It is not necessary (or desirable!) to include all your raw data in the paper, but it shouldbeclearhowtherawdatawereprocessedtoobtaintheincludedgraphs. For example, howmanytrialscontributedtoeachdatapointanderrorbar? Howwere importantquantitiesmeasured? • Explainthesourceofanyquoteduncertaintyestimates(statisticalvariation,instru- mentprecision,etc.) • Data should be analyzed (plotted, fitted, compared with theory, etc.) logically and understandably. Graphs should include titles, axis labels, units, and error bars. Fit formulas should correspond to appropriate theory. Data should be properly com- binedtogivefinalanswersthataddresstheoriginalquestionasfaraspossible. Un- certaintiesshouldbereasonablytreated. • Clearly state comparisons to theory or to “known” values, and include source cita- tionsorderivationsifnecessaryforthetheoryorknownvalues.Discussthestatistical significance(orlackthereof)ofyourresult(s). Conclusions • Whatlightdoyourdataandanalysisshedontheoriginalquestion/hypothesis? • Ifthereisafirmtheoreticalprediction,doestheexperimentagreewiththetheory?If so,withwhatprecisioncanyouconfirmtheory?Ifnot,byhowmuchisitoff(relative touncertainty)? • If the experiment was designed to measure an unknown quantity or effect, what is yourresult?Howprecisecanyouclaimitis? • What are the major sources of systematic and random error in your experiment? Whatextensions/improvementssuggestthemselvesifyouhad1or 2morelabses- sions? • PointouttherelevanceofyourworktofuturePhysics134labsortoothersituations ifappropriate. Citereferenceswhereappropriate e.g., lab manual, textbooks, and other sources of inspira- tion.Eachreferenceyouincludeinalistattheendofyourpapershouldbecitedatoneor moreparticularpointsinthebodyofthepaper. Physics 134 x

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