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Thin-Film Interference

  1. May 7, 2010 #1
    1. The problem statement, all variables and given/known data
    A soap film with different thicknesses at different placers has an unknown refractive index n and air on both sides. In reflected light it looks multicolored. One region looks yellow because destructive interference has removed blue (([tex]\lambda_{vacuum}[/tex]=469nm)) from the reflected light, while anotyher loks magenta because destructive interference has removed green (([tex]\lambda_{vacuum}[/tex]=555nm)). In these regions the film has the minimum thickness t required for the destructive interference to occur. Find the ration t[tex]_{magenta}[/tex]/t[tex]_{yellow}[/tex]

    2. Relevant equations

    [tex]\lambda_{film}[/tex] = [tex]\lambda_{vacuum}[/tex]/ n

    3. The attempt at a solution

    i know from the problem that m =1 because it says minimum thickness. But after that I do not know how I should set up the problem using algebra or physics.
  2. jcsd
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