Links to Web interference & diffraction tutorials
and other related Web resources
Simple interference effects for traveling waves: standing waves and "beats":
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Click to open the link. You may ignore the first animation, but the next one nicely
illustrates the mechanism that produces the "beats" effect: two waves with slightly
different frequencies periodically are "in phase", then "out of phase", then again
"in phase", and so on -- so their amplitudes periodically add up, or cancel out.
The third animation shows the interference of two waves traveling in opposite directions:
at some points the displacements always cancel out, forming "nodes" of a "standing
wave", and half-way between the nodes they preriodically add up/cancel out, forming
"antinodes" (note: there is an ongoing dispute whether the correct spelling is
"travelling" or "traveling" -- I've chosen the latter option).
Single-slit diffraction -- sites with Java animations:
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One site: Nice
graphics, you can "grab and turn" the setup (but I had
problems with changing the wavelength/slit width).
- Another site: you may change relevant
parameters such as lambda and the slit width.
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Yet
another site: my favorite because it shows the intensity distribution in a function
form, not only the on-screen appearance;
- And this
one is good, too, for the same reason as in Item #3;
- One more... An American Physics Society
site with a number of animated tutorials from different areas of physics, optics included -- however,
it requires a special "player", you'll have to download if it is not yet in your computer;
Circular aperture diffraction:
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One site...
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...and another one,
explaining the so-called "Airy patterns" -- an essential effect limiting the maximum magnification
of microscopes and telescopes.
For those who complain that there is not enough math in the Ph332 course: a link to a Georgia Tech PPT
presentation, discussing many aspects of interference & diffraction: