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Homework Help: Phase Change at reflection:

  1. May 22, 2008 #1
    1. The problem statement, all variables and given/known data

    Part of a longer question, what is the phase change, if any for a system of three substances of different n where there is surface reflection between n1 and n_f which is meant to constructively interfere with another surface reflection between n_f and n3.where n1 < n_f > n3 with n3 > n1?

    2. Relevant equations

    None, the text book I am using only says that when n1 = n3 there will be a pi phase change and there will be none if n1>n_f>n3 or n1<n_f<n3.

    3. The attempt at a solution

    None, other than an intelligent guess it will be some sort of function with 0 < f(n_f) < pi.
  2. jcsd
  3. May 22, 2008 #2
    Anyone? This is part of a much larger project and I can well assume that it is indeed pi, the point is that I don't want to make too many undue assumptions.
  4. May 22, 2008 #3
    When a light reflects on a material with higher refractive index it undergoes a phase change of pi in the other case the phase does not change, in your case there will be a pi change on n1, nf and no change at nf ,n3 so the phase change must be pi otherwise the interference would be destructive.
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