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Thread: 445nm beam collimation/correction

  1. #21
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    Quote Originally Posted by mccarrot View Post
    But do you really find it a problem during scanning?
    Have you ever had a customer saying, this beamshow sucks because I had seen "wings" around the red.
    Or these graphic really sucks because everything is red???

    I really don't see the problem.

    we now have affordable 445nm power with reasonable beam specs and we are nitpicking about something a normal person would never notice in a projector.

    Not personally no.. and I agree about these subtleties being nearly impossible to detect when used in a scanner, but others are far more picky. For them it might be worth investing a little time and effort into the pursuit of near-perfection. To me, all you need to do laser shows is a beam.. it doesn't matter if it's square, round, line, zig-zag, spiral or whatever.. just a beam with low(ish) beam diameter and divergence and good modulation response..

  2. #22
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    Oh, and when adjusting the collimator just slightly out of focus you will get a better beam profile/divergence at distance. just try it.

  3. #23
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    I updated the first post with some new data (Power chart, pics. comments).

    cheers!

    Frank

  4. #24
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    My plan is to knife edge 2 or 3 445nm diodes and use the O-Like lens and then to put a 3mm pinhole as close to the scanners as possible. Wouldn't that just give me a nice round 3mm beam into the scanners?

    I really don't care how much power I lose, I just want a nice clean beam going into the scanners.

    Gene

  5. #25
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    Quote Originally Posted by mccarrot View Post
    Oh, and when adjusting the collimator just slightly out of focus you will get a better beam profile/divergence at distance. just try it.

    I do believe this might supply a clue to where the trash is coming from !

    How much is "slightly" ? and how much power do you lose as a result ? (approx. naturally)

    I don't really trust the edges of the diode much but I do like more power.

    Cheers
    Last edited by catalanjo; 10-25-2010 at 07:05. Reason: power loss ?

  6. #26
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    mixedgas is offline Creaky Old Award Winning Bastard Technologist
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    Quote Originally Posted by Phredy1 View Post
    My plan is to knife edge 2 or 3 445nm diodes and use the O-Like lens and then to put a 3mm pinhole as close to the scanners as possible. Wouldn't that just give me a nice round 3mm beam into the scanners?

    I really don't care how much power I lose, I just want a nice clean beam going into the scanners.

    Gene
    I tried it, without doing Fourier transform optics on it, ie 2 lens, special pinhole between the lenses, loose one hell of a lot of power, the pinhole does not work well. Even with a seriously "Phatt" adjustable pinhole that needs Pdiddy's credit card to buy, , I managed to score some serious diffraction right around where the "cleanup" starts. Ie you can only clean up at one distance in space, and then your not scoring well.


    A rought explanation is to think of the bad rays coming from the middle of the beam, and only escaping at a beam waist that somehow exists in the far field. Its not your normal "Gaussian" beam by a long ways, its a overlay of a whole bunch of them in parallel or some other nause. (Greatly oversimplified explanation)

    Dr Lava's lenses work well, IMHO. I have not yet seen Badger's prisms.

    Try running the diode at far less current, but if you wanted a single line 488 aircooled you would have bought one, right?

    Steve

  7. #27
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    Default collimating the blue

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ID:	22382Hi all,

    i will build a blue 445nm 1W soon,Click image for larger version. 

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ID:	22381 i will use the McCarrot lens/collimator/fitting for 11mm block and prisms at the end, here is a picture of the block, got it from the NL LEM Ilpendam 2010, i guess McCarrot uses the same for his setup and i can confirm that it gives a very good beamshow, you can also judge by the photo's and video's taken at the LEM which are posted on the FTP server.
    As soon as i have completed the blue i will share my findings.

  8. #28
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    Laser Warning

    I just want to comment to the photo's michel Rietveld posted.

    Those blocks are universal blocks, you can use them to combine 1, 2 or 3 blue diodes. In front there is a place to clamp the prismpair from the groupbuy (no need for glueing the prisms )

    Or you can use them to combine 3 red diodes.
    For red you can use 2 methods:
    1 knive edge 2 vertical red and and combine a horizontal red with a PBS for the perfect beam (2,5mmx2,5mmx0,8mrad)

    or you can knive edge 3 beams so you can combine another block so you can use 6 diodes or even 12 diodes.

    And the best thing it is cheap!


    The beam on the right with the good divergence is from this modules

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  9. #29
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    Quote Originally Posted by mccarrot View Post
    And the best thing it is cheap!

    How cheap? I want one!

  10. #30
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    We are thinking of a price of 60-65 euro/block (ex vat) soon available trough my webshop.

    We are thinking of offering sets as you also need a minimount and collimators with this setup.

    I have attached a better picture, please note the price is only for the metal work.
    The prism, collimater and mirrormounts are not included in this price.

    size is 70x40mm and with a TEC fitted the beam hight will be 29mm

    Last edited by mccarrot; 12-18-2010 at 09:05.

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