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View Full Version : Anyone remember how to prove Babinet's principle through superposition? (diffraction)


KillaMarcilla
May21-03, 02:06 AM
Yo, d00dz

I'm kind of stumped on this problem on my homework: "A monochromatic beam of parallel light is incident on a hole of diameter a >> wavelength. Point P lies in the geometrical shadow region on a distant screen. Two obstacles are placed in turn over the hole. A is an opaque circle with a hole in it and B is the "photograhpic negative" of A (a circle with an opaque hole in it) Using superposition concepts, show that the intensity at P is indentical for each of the two diffracting objects A and B (Babinet's principle)"

I'm just clueless as to where to start on this.. I was about to fire up a point-by-point analysis, but this class doesn't really require knowledge of integration, so I don't think that's the right way to go about finding the answer

Can anyone lend a hand?

I'm going to stay up for a while seeing if I can't help anyone else on their homework, and then I'll get up in the morning early, in case any people in other time zones show up

Tom Mattson
May21-03, 08:13 PM
I think that page 5 of this document will help you:
http://www.upscale.utoronto.ca/IYearLab/intdif.pdf