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Homework Help: Wave dispertion related question

  1. Jan 22, 2006 #1

    the problem i have sounds something like that:

    there is a piece of glass with metal cover(on one side) in vacuum.
    light incident on metal surface.
    if you look at the glass from the metal surface side it appears red but when you look at it from other side it appears blue.
    given wave length of red is 700nm and blue 500nm.

    then there is two questions:
    1. explain the phenomena
    2. estimate metal surface width

    i find it difficult to explain this phenomena...
    right now my idea is that there is some cuttoff frequency(derived from dispersion relation) corresponding approximatly to red wavelength.. so that any light with wave length>~700 is reflected.
    but i don't know what to say about the blue color on opposite side

    can someone point me in the right direction?
    thanks a lot
  2. jcsd
  3. Jan 23, 2006 #2
    Sound to me like the photoelectric effect. If the metal has a work function equal to the energy of a single blue photon, then it may transmit blue photons onto the glass side, while it will reflect all the red, less energetic, photons.
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