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Thread: My 1W 445 Module build using 4x Anamorphic prisms

  1. #51
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    Default Stupid title here

    Dunno ??? I have not knife edged yet....just got talking with Dave at LSP on which bits to use...I would imagine it doed not matter...side by side....or upper/lower....very slight overlap....and...Sheeeezam !!! close to a box shape....I assume this is correct ???? comments from more experienced members ???? Thanx.

    CDBEAM
    Beam Axiom #1 ~The Quantum well is DEEP ! Photons for ALL !!
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    Beam Axiom #2 ~Yes...As a matter of fact...I DO wear tinfoil on my head !!
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    Beam Axiom #3 ~Whe'n dout...Po ah Donk awn et !!
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    Beam Axiom #4 ~A Chicken in every Pot, and a Laser Lumia in every Livingroom !!
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    Beam Axiom #5 ~"Abstract Photonic Expressionism"....is "Abstractonimical" !!
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    Beam Axiom #6 ~ "A Posse ad Essea" ~ From being possible to being actual ...is the beam target !

  2. #52
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    Jim, the reason the SA is corrected is that it's easier to tame the FA first with a commonly available focal length collimating lens to a spec that's easily good enough for our purposes, then use correction optics to sort out the SA.
    Doing it the other way round and handling the SA with the collimator will require a much longer FL and bigger diameter lens (to capture the rapidly growing FA) and now you need bigger correcting optics to get the now huge diameter FA under control.

    Using one set of prisms moves these diodes towards circular, adding another set to the other axis will improve things further (if you have it set up right) but I still don't think you will ever get a perfect beam, remember the emitter is far from square.
    Just throwing it out there.. maybe we're trying to strive too hard for perfection? Maybe just picking the right collimator and applying some prism/cylinder lens correction to the SA will be plenty good enough? That along with a slight focus adjustment to give you a nice square spot at your chosen distance would be a very good beam, and a million times better than the 3-4mR 635nm reds we have all put up with for years with their heavy diameter, divergence, astigmatism/waist characteristics.
    Out of a pair of knifed 445nm diodes I am getting about a 4mm beam with 1mR (26mm spot at 21m) with Aixiz collimators, and I think it looks bloody good. Yes the beam flattens a bit along the path (waist) but unless I walk along a static beam bobbing around like some kind of nutty duck I can't see it and really can't see it ruining an otherwise excellent graphics show.

    I can see no real advantage in using 2 sets of prisms on the same axis TBH, unless for some reason you need a massive amount of magnification. Just use one set and rotate the first prism to increase the magnification and the second prism to turn the beam back on track. I have heard of some people seeing quite high losses, but are the prisms set up right? With Aixiz collimators I'm seeing about 3% losses through the prism set. With shorter FL collimators the wider angles mean losses will increase and maybe double to 6-7% or even more for very short FL collimators. The prism angles and relationship to one another are key to the performance with these things, click on the 'Specifications' tab of these prisms from Edmund, it'll give you an idea of the angles. Orientate them in the same way with the beam entering left and exit right for the most compact and efficient assembly -
    http://www.edmundoptics.com/onlineca...productID=2429

  3. #53
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    Thanks for that Simon, thats cleared up a lot of wayward thoughts I was having about it all.
    I am going in the shed in a while to try the extra 2 prisms in situe now the glue has set - the findings will be shared
    --------------------
    My Brain urt's!

    Continuously in Awe! of (H)Al, the Photonlexicon Font of Complete Knowledge - The (H)Al'PL Database of complete puss that no one needs to know or ever trusts as he ain't really got a Scooby doo about now't!

  4. #54
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    Here are some photo's of the head just about finished, apart from a roof that is
    Also, a few photo's of the beam at 10m.
    I am getting 1150mW output after correction optics which i am more than happy with.
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    --------------------
    My Brain urt's!

    Continuously in Awe! of (H)Al, the Photonlexicon Font of Complete Knowledge - The (H)Al'PL Database of complete puss that no one needs to know or ever trusts as he ain't really got a Scooby doo about now't!

  5. #55
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    Great nice beamshots!! Could you measure the beamsize after 10 meters just to compare notes?

    Looking good smogthemog

  6. #56
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    you guys are doing some great work over there!
    Pat B

    laserman532 on ebay

    Been there, done that, got the t-shirt & selling it in a garage sale.

  7. #57
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    Thanks Pat.

    Built up the Diode & TEC driver block this evening and accidentally fried my TEC while doing it
    Thats what happens when you are listening to music and not paying attention to what you are doing

    Pic's below:
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    Last edited by smogthemog; 08-30-2010 at 08:42.
    --------------------
    My Brain urt's!

    Continuously in Awe! of (H)Al, the Photonlexicon Font of Complete Knowledge - The (H)Al'PL Database of complete puss that no one needs to know or ever trusts as he ain't really got a Scooby doo about now't!

  8. #58
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    Here's a little template I made to align the prisms.
    The magnifications are as follows, roughly:
    50 deg : 1.8
    53 deg : 2.0
    56.775 (Brewster0 : 2.3

    Hope this will help some people

    printed at the right size, the black patches should measure 4x2 cm
    Attached Thumbnails Attached Thumbnails Print prisms.pdf  


  9. #59
    swamidog's Avatar
    swamidog is online now Jr. Woodchuckington Janitor III, Esq.
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    Rich,

    it gets slightly warm (never hot) so I added a couple heat sinks.



    Quote Originally Posted by neutrino View Post
    Hey Swamidog,

    What current you running your 445 at in this setup? Does the diode holder get hot at all or are you TE cooling it?

    Cheers
    Rich
    suppose you're thinkin' about a plate o' shrimp. Suddenly someone'll say, like, plate, or shrimp, or plate o' shrimp out of the blue, no explanation. No point in lookin' for one, either. It's all part of a cosmic unconciousness.

  10. #60
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    A few more pictures of my Build and it then added into my projector. Sorry but no scanned shots as of yet as I have just coated my DT40 mirrors with first contact
    The beam shots will come later
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    --------------------
    My Brain urt's!

    Continuously in Awe! of (H)Al, the Photonlexicon Font of Complete Knowledge - The (H)Al'PL Database of complete puss that no one needs to know or ever trusts as he ain't really got a Scooby doo about now't!

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