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Confocal system - how to calculate depth of field

  1. Oct 5, 2010 #1
    Hello everyone,

    I'm new here. I hope someone can help me with my problem. I need to find DOF of the system shown in the picture below. This is infrared confocal system which works with broadband infrared source (3-8um wavelengths). The detector is high detectivity IR detector with the sensor size of 300 um x 300 um. The pinhole in the setup is 50 um in diameter.
    I've read in here http://www.microscopyu.com/articles/formulas/formulasfielddepth.html" [Broken] about DOF and I'm not sure how to apply this equation in my case. My particular questions are:
    1. The NA in the equation - how should I calculate it for my setup? Which NA is it?
    2. How to calculate this e?
    3. Which magnification should I use? In my case I've got M=2 from the detector side and 1.31 from the IR source side.
    4. Maybe there is another equation I could use which could be easier in my case?

    Thanks for your help,

    Attached Files:

    Last edited by a moderator: May 5, 2017
  2. jcsd
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