lab diffraction and interference

8/16/2019 Lab Diffraction and Interference

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Lab: Diffraction and InterferenceTable of Contents

Lab: Diffraction and Interference

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!rou: Pontillo" Listro" Hallo#ell" Dember Date: $ebruar% &" &(&

)*+ECTI,E: The urose of this e-eriment is to e-amine the diffraction and interference atternsformed b% laser li.ht assin. throu.h a sin.le slit" diffraction .ratin. and a double slit and /erif% that theositions of the minima or ma-ima in the resultin. attern match the ositions redicted b% theor%0 Inaddition" there #ill be a comarison bet#een the diffraction and interference atterns formed b% different#a/elen.ths of laser li.ht and different slit #idths1sacin.0

H2P)THESIS: )ur results should follo# the e3uation: 456d7sin891m #hich is deri/ed from the e3uation:d7sin6895m740 In these e3uations m is the inte.er of frin.es the frin.e is from the center one" 4 is the

#a/elen.th of li.ht" 8 is the an.le deri/ed from the arctan of the frin.e's distance and the len.th bet#eenthe slit1diffraction .ratin. and screen0 The d #ill chan.e for each method0 It #ill reresent the slit sacin.in the double slit diffraction" the #idth in the sin.le slit" and the difference in the lines of sacin. in thediffraction .ratin.0 )ur e-erimental #a/elen.th should match #ith the theoretical #a/elen.ths" and" asseen in the e3uation" red" #hich has the lon.est #a/elen.th" should ha/e the lar.est frin.e len.ths foreach resecti/e order of the inte.er0

ETH)DS1 ATE;IALS:In order to erform this lab" #e must first set it u b% lacin. an otics bench on a flat surface #ith anotics screen on one end of the bench0 Then #e lace a sin.le slit on the oosite end of the bench0)nce this is set u" shine a laser li.ht throu.h the sin.le slit in the direction to#ards the screen0 Theatterns #ill then be roduced on the screen0


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DATA:


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Anal%si:We #ere able to see from our results" different atterns associated #ith these e-eriment0$or the double slit interference: As 6d9 the slit sacin. increased" the frin.e distance decreased0 Sacin. #as increased from 0&= mm to 0= mm" and the frin.e distance decreased from &0( mm to 0> mm0 Also as #a/elen.th increased 6chan.in. the color of the li.ht9 the frin.e distance also increased0 ,iolet ? nm" !reen =@= nm" and ;ed = nm" the frin.e distance increased from ,iolet (0& mm to !reen &0( mm to &0= m

$or Diffraction !ratin.: As the .ratin. lines1cm 6a9 increases the frin.e distance decreases0 When BaB #s 0( mm and increased to 0@@mm" the frin.e distance decreased from &> mm to ( m

$or Sin.le Slit: When sin.le slit #idth is increased" the % 6frin.e distance9 #ill decrease0 When slit #idth is increased from 0& mm to 0? mm to 0 mm" the frin.e distance decreases from &( mm to ((0& mm to @0 m0Also as #a/elen.th increased 6chan.in. the color of the li.ht9 the frin.e distance also increased0 ,iolet ? nm" !reen =@= nm" and ;ed = nm" the frin.e distance increased from ,iolet &( mm to !reen


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&>0 mm to @?0= mm0

CALC


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DISC


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&0 The double slit

(0 It roduced a central band #ith dimmer bands arallel to it on each side0 Each band has

li.ht and dark saces #ithin it no#0

@0 The diffraction .ratin.

(0 This created dots on the screen on the same lane0

&0 ake a chart to describe the chan.es that occur #hen:

(0 the double slit #idth is increased

&0 the double slit searation is increased

@0 the slit #idth of the sin.le slit is increased

?0 the diffraction .ratin. lines1cm is increased

=0 the #a/elen.th of the li.ht source is increased

C)CL mm0 We are able to sho# that #e could use the t#o e3uations to.ether to find theta then #a/elen.th0

)nce findin. the frin.e distance and the distance bet#een the slit and the screen" #e #ere able to find the an.le" to

lu. into 4566#1d1a97sin891m0

The lab did ha/e error alon. #ith it0 )ur error ran.ed from =F&G The actual measurements #ere handFdra#n and it

#as /er% difficult to dra# the li.ht e-actl% because e/er% time #e #ould tr% to dra# the bands a hand #ould block the

li.ht a bit0 This error came mostl% from the small measurements #e #ere takin.0 The /alues #ere rou.h estimatescomared because of the small sacin. in bet#een these oints0 We had to kee reFmeasurin. to make sure our

measurements #ere accurate in accordance #ithin our e3uation0

This lab sho#s the roert% that li.ht can beha/e like #a/e and it is not onl% beha/in. article0 This is the

basic rincile behind #a/eF article dualit%" #hich can be used in electron microsco%" #here the small

#a/elen.ths associated #ith an electron can be used to see obects smaller than #hats /isible usin.

li.ht0 The double slit e-eriment #hich #e erformed is also a basis to 3uantum mechanics0

lab diffraction and interference

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