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Thread: Who's collimated what? (expert [experienced] advice needed pleez)

  1. #1
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    Default Who's collimated what? (expert [experienced] advice needed pleez)

    Hey Y'all-
    Who out there (or in here, @ PL, as the case may be) has taken a bare diode and sucessfully collimated it into a usable beam for shows? I've ex
    perimented and f
    ound the whole process
    to be
    fairly frustrating but interesting and a good learning experience about optical principles and properties. The average 635nm diode I think is
    8/31 degrees,
    hows about a 5/39. This is what I waz thinking about buying.. small losses would be acceptible, but losing too much from 150 mW would be
    very
    disturbing
    Any thoughts or advice?
    Thanx,
    Steve

    -edit- typing got screwed up because evey time I typed a letter, it erased the one b4 it- this has happened be4 and I cant fig out what does it ..
    Last edited by steve-o; 03-09-2008 at 13:01. Reason: typing-typos

  2. #2
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    Default

    WTF happened to your post?
    CLICKY!!!

    Admin: In the immortal words of Captain Planet: YOU HAVE THE POWER
    Admin: (To quit being a bitch)

  3. #3
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    Try pressing insert the next time. It's the key called "Ins" to the left of "Home" and above "Del".

  4. #4
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    Default

    Thanx I'll try that. Nobody got any info concerning collimating lenses and such ?

  5. #5
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    Default

    If the source is shiet - the beam will be shiet!
    The first law of Optical Physics
    I hired an Italian guy to do my wires. Now they look like spaghetti!

  6. #6
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    Ok Ok I'll repeat this again. There is 2 ways fighting red diodes. (No actually 3..third is 671nm) One is to collimate other is reverse telescope. Basically speaking if you put your telescope into collimation mode you will get a perfect dot at the end but very large exit beam. If you put your telescope into reverse telescope mode you will get a small exit beam but divergence will be bad if you didn't do it right. To successfully collimate for lasershows you will need largest galvo mirrors you can find and around 1.5x telescope in collimator mode.
    I hired an Italian guy to do my wires. Now they look like spaghetti!

  7. #7
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    Just listening to bonjovis "raise your hands" after watching Spaceballs for the 15th time.. but I digress.. ok, ok repeating again , I know about the rifle-scope collimating thing.. I was looking for new info- and as far as I can tell a 40 uM window and 5 degrees by 39 is bad ,and 7-9 x 29 is good but I'm talking about a diode here, not a he-ne ..

  8. #8
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    Lightbulb

    Steve, check out what LaserBen is selling... http://photonlexicon.com/forums/show...5820#post45820

    Will these help you out at all?

  9. #9

    Default

    Hi steve-o, it seem's that you are trying something that I expect to do soon . Responding your question I DID. First it took me a hard time to study and understanding what is divergence, astigmatism, axis and how they interact. When you say 40um 5/39 it almost match ML1468 from Modulight I've posted here: http://www.photonlexicon.com/forums/...ead.php?t=4127

    So I'm gona try to colimate this one, first we have one fast axis and a slow axis both generate two apparent focal points that do not coincide, this condition is called Astigmatism. This leads us to a particular case where we need two distinct cylindrical lenses, the lens closer to the laser collimates the fast axis and the other lens collimates the slow axis of the laser diode. (remember polarisation? we can colimate only one of the axis to obtain horizontal or vertical polarisation, essential to a pbs cube) So, the collimation of the 5 x 39 laser diode to the same divergence in both directions requires the focal length of the slow axis collimating lens to be 7,8 times larger than the focal length of the fast axis lens. The collimated beam is still elliptical and can be circularized using an anamorphic prism pair. either the major axis is compressed or the minor axis can be expanded to make a circular beam. In my case I've used two lenses and a pair of anamorphic prisms.

  10. #10
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    Do you have any pictures or drawings to share?

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