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Interference, Diffraction, Diffraction Grading

  1. Apr 23, 2004 #1
    Can someone explain to me how to compute the different items concerning interference, diffraction and diffraction grading. I an not able to understand my physics book.
  2. jcsd
  3. Apr 23, 2004 #2
    If you have two waves and combine them, they will interfere. If the peaks line up, it's constructive interference. This will also happen if one of the waves takes a path that is longer or shorter by a full wavelength, so the peaks again line up.

    You will get destructive interference if the path difference is half of a wavelength - the peak of one wave cancels with the trough of the other.

    The equations in your textbook are just applying those conditions to the geometry of the situation.
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