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Thread: CO2 Laser mirrors?

  1. #1
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    Default CO2 Laser mirrors?

    Hey guys, just bought a small sealed CO2 tube from eBay. My ultimate goal with this tube (Providing it arrives intact) is to build a XY table. However, the optics are quite expensive, and considering I'd need maybe 4 or 5 mirrors, ZnSe doesn't seem like the cheapest option ($200 ish for 4 mirrors). I know regular mirrors won't work, because the glass infront of the reflective coating is opaque, but how about first surface mirrors?

    I have also heard about salt mirrors, but I'm not sure if they are easily DIYable or efficient enough.

    Cheers,
    Dan

  2. #2
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    Default

    I'm not sure about normal front surface mirrors as I'm not sure what the coatings are made of, but as far as I'm aware metal coated mirrors can be used for 10.6uM.

    As far as salt mirrors went, I thought it was only OC mirrors that were made of salt, as it needs to pass *some* light, and glass coated mirrors would not do this.

    Hope that helps a little.

  3. #3
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    Copper! But you have to keep it from oxidising.

    Also gold is a really good IR reflector so maybe get one of those plating kits and plate a thin layer of gold over a suitable substrate (And unlike copper, oxidation will not be a problem)..

    Salt makes a decent window (but it is seriously hydroscopic), but I doubt that it makes a useful mirror.

    The Sci-Am CO2 laser used copper cavity mirrors with a salt crystal covering a pinhole in the front mirror to allow the beam to exit.

    For a mirror (as opposed to a lens) you dont need the substrate to be transparent at 10.6, you just need a coating that is reflective at 10.6um.

    Just some thoughts.

    Regards, Dan.

  4. #4
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    Quote Originally Posted by DMills View Post
    Copper! But you have to keep it from oxidising.
    Yep! I've actually polished flat old american pennies (made of copper, not zinc.) and made CO2 laser mirrors out of them.

  5. #5
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    Default Hard Drive Platters

    If I recall hard drive platters have been used with success from my alt.lasers time... Correct me if need be!

    -Adam
    Support your local Janitor- not solicited .

    Laser (the acronym derived from Light Amplification by Stimulated Emissions of Radiation) is a spectacular manifestation of this process. It is a source which emits a kind of light of unrivaled purity and intensity not found in any of the previously known sources of radiation. - Lasers & Non-Linear Optics, B.B. Laud.

  6. #6
    mixedgas's Avatar
    mixedgas is online now Creaky Old Award Winning Bastard Technologist
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    Co2 is so uncritical that even a piece of cleaned unetched PCB board works. If it was me, I'd go with the older platters. AL coated mirrors are not bad, either, at low powers.

    PS, Surplus shed has some "gold" coated mirrors.

    http://www.surplusshed.com/pages/item/l10043.html

    Steve
    Last edited by mixedgas; 11-21-2010 at 20:59.

  7. #7
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    If you have a machine shop in the area which has a CO2 cutter, they may have used ZnSe optics available. (lenses and mirrors) I went to a local shop here and scored a 1.5" x 5" FL lens which with cleaning is like new. AND FREE !!!

    HMike

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