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DCQE Question on Purpose of Glan Thompson Prisms

  1. Jul 23, 2013 #1
    I have a question regarding Kim et al DCQE experiment: http://arxiv.org/pdf/quant-ph/9903047v1 (also found at wikipedia.org). I have seen a number of (very) different schematics of the experiment. The best one reviewed by Dr. Kim is at: bottomlayer.com/bottom/kim-scully/kim-scully-web.htm However, I still do not get the Glan Thompson Prism (Prisms? I have seen both one or two in schematics). In the original paper the authors say, "A Glen-Thompson prism is used to split the orthogonally polarized signal and idler." Is this to say that all the "signal" photons are of the same polarization as are all the "idler" That is to say, are all the photons in the signal path "p" polarization, and all the idler path "s" polarization?
    P.S. Is there a photo of the original experiment anywhere?
  2. jcsd
  3. Jul 23, 2013 #2


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    Science Advisor

    Welcome to these forums.

    Be careful with that site. Many of the claims there are quite off the track.

    In type II phase matching the two emitted photons have different polarizations. The Glen-Thompson prism is just a polarizing beam splitter which sends photons of one polarization one way and photons of the other polarization the other direction. Therefore the GT-prism causes spatial separation of the two polarizations and "divides" the photons into signal photons going one way and idler photons going the other way.

    I am not aware of one.
  4. Jul 23, 2013 #3
    Thanks that helps...
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