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I Creating a two lens system of tunable focal length

  1. Jul 10, 2017 #1
    I would like to reduce the beam size of a laser by a factor of 10, with the purpose of replacing a long (750 mm) lens with a more compact design.

    Ideally I'd make a Galilean lens pair where the ratio of the focal lengths are 10:1 to produce a small collimated beam. However, I think I could achieve my desired result (small beam just over some length) by using e.g. a 2:1 lens pair and moving the diverging lens "too close" to the converging lens, achieving a gentle focus and long confocal length.

    Questions: How would one calculate the Gaussian beam parameters (waist, Rayleigh length, etc.) given the combined focal length 1/f= 1/f1 + 1/f2 -d/(f1*f2)? Would I use it "straight" in those formulas?

    Thank you!
    Last edited by a moderator: Jul 10, 2017
  2. jcsd
  3. Jul 15, 2017 #2
    Thanks for the thread! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post? The more details the better.
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