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Half-Silvered Mirrors Inverting Photon Waves

  1. Jun 23, 2011 #1
    Why do only HALF-silvered mirrors invert the photon waves? Why don't fully slivered mirrors do the same thing? And why do the waves not invert when hitting the half-silvered mirror from the non-silvered side? Was this rule (that half-silvered mirrors invert the wave) invented to explain the destructive interference in the Mach-Zehnder interferometer experiments or is there some logical basis to it?
  2. jcsd
  3. Jun 24, 2011 #2

    Claude Bile

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    If you have a fully silvered mirror, you do not undergo any path encoding; that is, all photons travel the same path and thus the photon wave cannot be said to be inverted with respect to anything!

    On the other hand , if you have a 50% mirror, half the photons travel down path A, while half travel down path B. The reflected photons will be inverted compared to the transmitted photons; so when these paths are recombined, they will potentially sum to zero resulting in non-classical interference.

  4. Jun 27, 2011 #3
    Thanks, Claude. That makes sense. But why don't the reflected photons invert when they hit the half-silvered mirror from the other side?! There are, after all, other photons that are transmitted through the mirror. The path is split in two but no inversion takes place. This seems absurd to me. How can it be explained?
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