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Link to description of detector type for double-slit experiment

  1. May 9, 2012 #1
    Can someone supply me with a link to a good article or book, or anything, that gives details on the type of detector that determines "which way" in experiments where the double-slit interference pattern is cancelled?

  2. jcsd
  3. May 9, 2012 #2


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    As a general rule, no one actually bothers to detect which-way information in these experiments. It is simply the idea that the setup is changed such that in principle, this information is available. That is enough.

    For example: Sometimes, in a setup with a stream of photons going through a double slit, they place polarizers over each slit. When the polarizers are crossed, there is no interference. (When parallel, there is.) And yet of the final pattern, no one did anything to see which slit any particular photon went through.
  4. May 9, 2012 #3
    While it walks further away from the intent of my question I cannot help but ask:
    What then would be the result of placing polarizers in front of two distinct sources (such as visible lasers) that would normally produce an interference pattern.

    Would the interference pattern go away if the polarizers were set to "conflicting" polarization in this case also? If so what does that tell us about use of these devices in the double split experiment?

    If I might be so bold, for someone who has little formal training in physics, to say that it continues to amaze me that experimenters do things to particles or photons in transit and are stupefied when the object entity does not behave thereafter as per normal.

    Thanks for finding time to respond. I have found this an interesting subject for many years.

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