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Mirau White Light Interferometer. Light Source?

  1. Jun 9, 2014 #1
    Hi everyone,
    I'm building a white light interferometer and need help choosing and finding a white light source.

    I'm using this mirau objective:


    Here is the setup:


    I know that the light source will have to be collimated and go through an aperture stop, field stop, bandpass, etc. I was hoping that there was a white light laser that does these steps already so that I don't have to work with several different lenses and build a setup for them. Such a laser must exist, no? Does anyone know where I can find one? Ideally one that is 100-200 Watts? I've looked all over but am having trouble finding an manufacturer that makes what I'm looking for.

    Are there any important steps that I'm missing? Should a collimated white light beam do the job?

  2. jcsd
  3. Jun 9, 2014 #2
    200 Watts? (!) are you doing interferometry on the moon? That level of power on a laser is used to cut steel. Further, white lasers are a special purpose rarity. I've not heard of anyone using them for interferometry. Its not necessary. Why do you want to use white?
  4. Jun 10, 2014 #3
    I'm not sure about the wattage but i know that white light interferometry is a common practice.

    http://www.laserfocusworld.com/articles/print/volume-37/issue-9/features/interferometry/interferometric-approaches-each-have-advantages.html [Broken]

    White light is more suited to rougher surfaces which would be appropriate for my purpose because the surface I'm looking at will have ┬Ám variations.
    Last edited by a moderator: May 6, 2017
  5. Jun 10, 2014 #4
    oh and yes I was totally off with the power of the laser
  6. Jun 10, 2014 #5
    from what I've seen, white light interferometry is not done with a laser. And that includes your sources that you posted. reread the first page of your document from fp.optics. White lasers are a relatively recent invention. And I believe it is a much more complicated solution.
    Last edited: Jun 10, 2014
  7. Jun 10, 2014 #6
  8. Jun 10, 2014 #7
    I was under the impression that the steps described in the diagram (before the light even reaches the beam splitter) were steps that were typical of those carried out in a laser before it exits the laser.
  9. Jun 10, 2014 #8
    Last edited: Jun 10, 2014
  10. Jun 10, 2014 #9
    most of that is totally unnecessary if your light starts out monochromatic and coherent. For laser interferometry, all you need is the laser, a beam splitter, a lens, and a mirror.
  11. Jun 10, 2014 #10
  12. Jun 25, 2014 #11
    White Light Interferometry

    Hi adamjts,

    I'm a Product Support Engineer who works at Edmund Optics. I've been following your posts above and noticed that you're interested in White Light Interferometry. In terms of the setup that would go with the interferometry objective above, you're definitely on the right track. You would need an illumination source and a way to mount it inline. We have suggested parts for the illumination, inline mechanics, and the mounting. This would make sure that you don't have to build everything from scratch. If you're interested to discuss this further, please feel free to email me at this address. I look forward to working with you on your application.

  13. Jun 25, 2014 #12


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    Gold Member
    2017 Award

    hi adamjts

    on pages 18 and 19 of that document in your post #6

    its shows their setup, they are using a white light LED ( Light Emitting Diode)

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