© 2010 Pearson Education, Inc. PowerPoint ® Lectures for College Physics: A Strategic Approach, Second Edition Chapter 17 Wave Optics

© 2010 Pearson Education, Inc. Slide Wave Optics

© 2010 Pearson Education, Inc. Slide 17-3

© 2010 Pearson Education, Inc. Slide 17-4

© 2010 Pearson Education, Inc. Water Waves Spread Out behind a Small Opening Slide 17-9

© 2010 Pearson Education, Inc. Index of Refraction Slide 17-10

© 2010 Pearson Education, Inc. Light Waves Also Spread Out Behind a Very Narrow Slit Slide 17-11

© 2010 Pearson Education, Inc. Young’s Double-Slit Interference Experiment Slide 17-12

© 2010 Pearson Education, Inc. Analyzing the Double-Slit Experiment Slide 17-13

© 2010 Pearson Education, Inc. Bright and Dark Fringes in the Double-Slit Experiment Slide 17-14

© 2010 Pearson Education, Inc. Example Problem Two narrow slits 0.04 mm apart are illuminated by light from a HeNe laser (λ = 633 nm). A. What is the angle of the first (m = 1) bright fringe? B. What is the angle of the thirtieth bright fringe? Slide 17-15

© 2010 Pearson Education, Inc. The Diffraction Grating Slide 17-16

© 2010 Pearson Education, Inc. Bright Fringes for a Diffraction Grating Slide 17-17

© 2010 Pearson Education, Inc. The Intensity Pattern Due to a Diffraction Grating Slide 17-18

© 2010 Pearson Education, Inc. The Fringes Become Very Narrow as the Number of Slits is Increased Slide 17-19

© 2010 Pearson Education, Inc. A Diffraction Grating Splits Light into the Wavelengths That Make It Up Slide 17-20

© 2010 Pearson Education, Inc. Thin-Film Interference Slide 17-21

© 2010 Pearson Education, Inc. Phase Changes Due to Reflection Slide 17-22

© 2010 Pearson Education, Inc. Analyzing Thin-Film Interference Slide 17-23

© 2010 Pearson Education, Inc. Slide 17-24

© 2010 Pearson Education, Inc. Checking Understanding A film of oil (n oil = 1.2) floats on top of an unknown fluid “X” (with unknown index of refraction n x ). The thickness of the oil film is known to be very small, on the order of 10 nm. A beam of white light illuminates the oil from the top, and you observe that there is very little reflected light, much less reflection than at an interface between air and X. What can you say about the index of refraction of X? A. n x > 1.2 B. n x < 1.2 C. n x = 1.2 D. There is insufficient information to tell. Slide 17-25

© 2010 Pearson Education, Inc. Answer A film of oil (n oil = 1.2) floats on top of an unknown fluid “X” (with unknown index of refraction n x ). The thickness of the oil film is known to be very small, on the order of 10 nm. A beam of white light illuminates the oil from the top, and you observe that there is very little reflected light, much less reflection than at an interface between air and X. What can you say about the index of refraction of X? A. n x > 1.2 B. n x < 1.2 C. n x = 1.2 D. There is insufficient information to tell. Slide 17-26

© 2010 Pearson Education, Inc. Single-Slit Diffraction Light passing through a narrow slit spreads out beyond the slit. Slide 17-27

© 2010 Pearson Education, Inc. Analyzing Single-Slit Diffraction Slide 17-28

© 2010 Pearson Education, Inc. Single-Slit Diffraction: Positions and Intensities Slide 17-29

© 2010 Pearson Education, Inc. Circular-Aperture Diffraction Slide 17-30

© 2010 Pearson Education, Inc. Checking Understanding The fringe pattern below could be due to A.a single slit or two slits. B.ten slits. C.either two slits or ten slits. D.either one slit or two slits. Slide 17-31

© 2010 Pearson Education, Inc. Answer The fringe pattern below could be due to A.a single slit or two slits. B.ten slits. C.either two slits or ten slits. D.either one slit or two slits. Slide 17-32

© 2010 Pearson Education, Inc. Checking Understanding If the two slits shown are illuminated in turn by a broad laser beam, which produces a wider illuminated region on the screen at the right? A.The 1-cm-wide slit. B.The 2-cm-wide slit. C.There’s no way to tell with the information given. Slide 17-33

© 2010 Pearson Education, Inc. Answer If the two slits shown are illuminated in turn by a broad laser beam, which produces a wider illuminated region on the screen at the right? A.The 1-cm-wide slit. B.The 2-cm-wide slit. C.There’s no way to tell with the information given. Slide 17-34

© 2010 Pearson Education, Inc. Example Problem What is the diameter of an aperture for which the diffraction central maximum is the same size as the geometric image of the hole? Slide 17-35

© 2010 Pearson Education, Inc. Summary Slide 17-36