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Homework Help: Quick question regarding polarizer

  1. Aug 14, 2013 #1
    This is not really a homework but I would like to confirm my understanding on the principle of a wire grid polarizer. For the polarizer to filter the polarization of EM wave, waves with e field parallel to the grid will cause the electron to oscillate in the same direction so the wave is reflected while another wave with orthogonal e field will pass through.

    Is this explanation correct? If so, why does the electron movement reflect the incident wave and not radiate the wave and allows it to pass through the polarizer?
  2. jcsd
  3. Aug 14, 2013 #2
    Your explanation is correct.

    As to why it reflects, consider that in the direction parallel to the E field, it behaves exactly like a an ordinary metallic surface behaves. Then the question is reduced to "why do metals reflect". Can you answer this question?
  4. Aug 15, 2013 #3
    I have no idea why metals reflect. I always thought that at the interface you have to use the continuity condition to describe the parallel and perpendicular components of the E field.
  5. Aug 16, 2013 #4
    The basic (classical) idea of metallic reflection is that free electrons oscillate with the frequency of incident light.

    The theory works well up to the infrared frequencies. For more information, here are some keywords: Drude model; Hagen-Rubens relation.
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