Interference & Diffraction

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Video Clips

Interference (8.02, Spring 2002)

Video RealVideo®
10:40 minutes (0:49 - 11:29)

Definition for two sources of traveling waves with the same frequency separated by some distance. Conditions for constructive and destructive interference; nodes and maxima; interference patterns.

Prior Knowledge: None
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Video RealVideo®
4:59 minutes (11:29 - 16:28)

Creating an interference pattern in a pool of water by tapping on the surface at two points. Also includes a slide of a butterfly in a pond.

Prior Knowledge: Interference (0:49 of video lecture 33)
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Video RealVideo®
6:59 minutes (16:28 - 23:27)

Conditions in terms of angle θ between the center of the two sources and the point at which the interference is being measured.

Prior Knowledge: Interference (0:49 of video lecture 33)
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Video RealVideo®
9:05 minutes (23:27 - 32:32)

Finding locations in the lecture hall where constructive and destructive interference occurs from two speakers placed at the front of the room.

Prior Knowledge: Interference (0:49 of video lecture 33)
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Young's Double Slit Experiment (8.02, Spring 2002)

Video RealVideo®
8:03 minutes (32:32 - 40:35)

The original experiment used to demonstrate that light was a wave, performed here by shining a red laser through two small slits.

Prior Knowledge: Interference (0:49 of video lecture 33)
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Video RealVideo®
3:56 minutes (40:35 - 44:31)

Comparing interference patterns for red, blue, and white light, including a slide showing all three.

Prior Knowledge: Interference (0:49 of video lecture 33)
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Video RealVideo®
7:06 minutes (44:31 - 51:37)

Tracking the interference pattern from two sources of radar waves using a receiver that slides along a track.

Prior Knowledge: Interference (0:49 of video lecture 33)
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Multi-Slit Interference (8.02, Spring 2002)

Video RealVideo®
7:48 minutes (0:00 - 7:48)

Conditions for constructive and destructive interference for light shining through N slits.

Prior Knowledge: Interference (0:49 of video lecture 33)
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Video RealVideo®
9:16 minutes (7:48 - 17:04)

Interference pattern for a red laser and a white light shining through a fine grating.

Prior Knowledge: Multi-slit Interference (beginning of video lecture 34)
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Video RealVideo®
6:04 minutes (17:04 - 23:08)

Using a lens to see an interference pattern at a much closer distance. Demonstration uses the lens of the eye and an individual grating to view the pattern for a white light and a neon light.

Prior Knowledge: Multi-slit Interference (beginning of video lecture 34)
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Diffraction (8.02, Spring 2002)

Video RealVideo®
7:00 minutes (23:08 - 30:08)

Definition, with conditions for maxima and minima of this single-slit interference and a plot of the diffraction pattern.

Prior Knowledge: None
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Video RealVideo®
6:00 minutes (30:08 - 36:08)

Showing that for a narrower slit the diffraction pattern becomes wider using a variable width slit and a green laser.

Prior Knowledge: Diffraction (23:08 of video lecture 34)
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Angular Resolution (8.02, Spring 2002)

Video RealVideo®
9:50 minutes (36:08 - 45:58)

Diffraction for a circular opening, and discussion of angular resolution for distinguishing between two light sources. Includes the Rayleigh criterion and discussion of angular resolution for telescopes on earth and in space.

Prior Knowledge: Diffraction (23:08 of video lecture 34)
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Video RealVideo®
5:32 minutes (45:58 - 51:30)

Testing the eye's angular resolution by looking at a series of pairs of pinholes with different separations to see which ones appear as two distinct light sources.

Prior Knowledge: Angular Resolution (36:08 of video lecture 34)
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Lecture Notes

Interference (8.02T, Spring 2005)

Document PDF - 1.4 MB
Page 1 to page 18

Introduced as a method for measuring the small wavelength of visible light. Diagrams and link to a visualization illustrating interference from light passing through two slits. Definition of and conditions for interference. Constructive vs. destructive interference. Phase shifts, iridescence, and extra paths; all with equations and diagrams.

Prior Knowledge: Waves (Pages 11-26 of presentation 28)
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Interference for Two Sources (8.02T, Spring 2005)

Document PDF - 1.4 MB
Page 18 to page 28

Equations and diagrams for calculating the interference from two sources, using examples of microwaves and visible light.

Prior Knowledge: Interference (Pages 1-18 of presentation 33)
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Diffraction (8.02T, Spring 2005)

Document PDF - 1.4 MB
Page 28 to page 38

Definition, with diagrams. Equations and diagrams for single slit diffraction and double slit diffraction/interference. Statement of Babinet's Principle.

Prior Knowledge: Interference (Pages 1-28 of presentation 33)
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Review: Waves (8.02T, Spring 2005)

Document PDF#
Page 18 to page 21

Equations for a traveling sine wave, electromagnetic waves, interference, and diffraction

Prior Knowledge: Material is from presentations 28 and 30.
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Exam Problem: Interference (8.02T, Spring 2005)

Document PDF#
Page 43 to page 46

Finding the number, width, and separation of slits given a picture of a diffraction pattern of red light.

Prior Knowledge: Interference and Diffraction (Pages 1-38 of presentation 33)
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Interference (8.02T, Spring 2005)

Document PDF
Page 1 to page 2

Definition, with diagrams of constructive and destructive interference. Two-slit interference and diffraction are defined with equations and diagrams.

Prior Knowledge: None
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Online Textbook Chapters

Interference (8.02T, Spring 2005)

Document PDF
Page 2 to page 12

Superposition of waves; double-slit and triple-slit experiments with intensity distributions and wavelengths.

Prior Knowledge: EM waves
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Worked Light Problems (8.02T, Spring 2005)

Document PDF
Page 26 to page 32

Double-slit experiment, phase difference, interference, and intensity in diffraction.

Prior Knowledge: Interference; diffraction
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Practice Problems

Interference and Diffraction (8.02T, Spring 2005)

Document PDF
Problem 1 to problem 12

Six questions with answers and explanation.

Prior Knowledge: None
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Angular Resolution of Telescopes (8.02, Spring 2002)

Document PDF
Problem 3

Finding angular resolution for single telescope, then two telescopes as interferometer.

Prior Knowledge: None
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Document PDF
Problem 6

Finding angular resolution for ground-based and space-based telescopes.

Prior Knowledge: None
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Java Applet

Two-Dimensional Waves (8.02T, Spring 2005)

Java Applet Java Applet
Requires Java Virtual Machine

Applet showing the propagation of waves in two dimensions to illustrate the properties of interference, diffraction, and reflection.

Prior Knowledge: Interference (Pages 1-18 of presentation 33)
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MIT courses referenced in this section: