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Homework Help: WFE of a Mirror

  1. Jan 29, 2015 #1
    Thank you all for any help or advice you can give.

    1. The problem statement, all variables and given/known data

    What is the fabrication Wavefront error (WFE) of a mirror with a PV surface error of 1 um? Express your answer in terms of RMS waves at lambda = 0.633 um

    2. Relevant equations

    3. The attempt at a solution
    I know to start by calculating the WFE. I know the SFE=1um
    WFE=2um PV

    I dont know how to convert PV into RMS. Everything I've read says there is no set ratio between PV and RMS measurements. But that values from 3-5 are commonly used depending on the surface error. So I'm a little confused.

    Thank you again for any help you can offer.
  2. jcsd
  3. Jan 30, 2015 #2
    I don't know much about optics, but to me it seems like the problem statement is missing some context.

    There isn't any mention of a specific type of surface aberration, or perhaps some kind of approximation based on some assumptions you've discussed in your course?
  4. Jan 30, 2015 #3
    Thank you for the response.
    I feel the same way thats why I was asking. There is no mention of specific type of aberration in the question, and as far as I can tell from the reading you can use any number between 3-5 depending on the different aberration you are dealing with. I was hoping someone was familiar with optical engineering and could let me know what I'm missing. Thanks again.
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