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Thread: lightspace ascent-x series

  1. #41
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    The prisms correct the fast axis by expanding the beam and reducing the divergence to be closer to the slow axis.
    Increasing beam size reduces divergence, and vice versa.
    On high power projectors by the time you get a little away from the projector the beams are sufficiently diverged to blend together.
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    You are using Bonetti's defense against me, ah?

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  2. #42
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    Quote Originally Posted by norty303 View Post
    The prisms correct the fast axis by expanding the beam and reducing the divergence to be closer to the slow axis.
    Increasing beam size reduces divergence, and vice versa.
    I don't really know what a "fast" and "slow" axis is.
    When you say increasing beam size reduces divergence, you're only talking about using the prism pair right?
    Sorry this is probably a stupid question.

    On high power projectors by the time you get a little away from the projector the beams are sufficiently diverged to blend together.
    Oh, OK. Some people told me or I interpreted it wrongly that you need a beam expander if you want the beam to appear blended, by shrinking the beam array, in effect also shrinking the gaps, to appear as one.
    What you said makes sense now that I think about: as the beams diverge a little (grow in diameter) their distance from each other doesn't change so ultimately the beam diameter will grow enough to fill the gap between the beams.
    I guess a beam expander is used when the combined array is just too big for the scanner mirrors (of course and/or when you want to decrease divergence) maybe that was what I was told.
    Thanks for the explanation.

    And sorry for going off topic.

  3. #43
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    Why not search for the things you don't understand, they're well discussed on the forum and elsewhere
    Fast and slow axis refers to the divergence, and it means exactly what it says. It's the reason multi mode diodes make a rectangle at distance when used with just a regular collimator.
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    You are using Bonetti's defense against me, ah?

    I thought it fitting, considering the rocky terrain.

  4. #44
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    Quote Originally Posted by norty303 View Post
    Why not search for the things you don't understand, they're well discussed on the forum and elsewhere
    Hehe, sorry about that, usually the forum search works poorly for me and googling brings up all sorts of unrelated stuff like laser engraving so I didn't bother trying this time, but this time I actually got the info.

    Fast and slow axis refers to the divergence, and it means exactly what it says. It's the reason multi mode diodes make a rectangle at distance when used with just a regular collimator.
    Okay, I guess I understand now. these powerful diodes diverge in the X axis a lot and have long "feathers" just after few meters (like my 300mW shitty red module in my projector). The prism pair doesn't affect the "Y axis", but shrinks the beams in the "X axis", thus making the dot appear more of a circle than a long horizontal line. Got it.


    Do these modules use active cooling?
    And btw, why so many lower power red diodes instead of few 700mW and a prism pair like they did for the green and blue? Wouldn't it be more cost effective and less time consuming for them?

  5. #45
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    Quote Originally Posted by blue View Post
    Hehe, sorry about that, usually the forum search works poorly for me and googling brings up all sorts of unrelated stuff like laser engraving so I didn't bother trying this time, but this time I actually got the info.


    Okay, I guess I understand now. these powerful diodes diverge in the X axis a lot and have long "feathers" just after few meters (like my 300mW shitty red module in my projector). The prism pair doesn't affect the "Y axis", but shrinks the beams in the "X axis", thus making the dot appear more of a circle than a long horizontal line. Got it.


    Do these modules use active cooling?
    And btw, why so many lower power red diodes instead of few 700mW and a prism pair like they did for the green and blue? Wouldn't it be more cost effective and less time consuming for them?

    the lightspace modules do have active cooling, and yes there's some feathering around the spot. most evident in the red. it would be worth trying to spatial filter them.
    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.

  6. #46
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    Is the cooling in these pure diode modules for keeping stable wavelength or for the duty cycle? I thought the heatsinks are enough for these diodes and wavelength isn't such an issue as with DPSS ones.

    And yeah swamidog, I can cut the "feathers" but I don't like loosing power on that. Maybe I'll just find an inexpensive prism pair to use with my cheap chinese module and use those.

  7. #47
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    It is possible to do a certain amount of beam cleaning on the multi mode Reds by simple masking. I added BlackTak on the cylinder lenses to remove the worst of the wings. 30 second cheap fix
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    You are using Bonetti's defense against me, ah?

    I thought it fitting, considering the rocky terrain.

  8. #48
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    LDs like to be cool, so better life expectance and more stable power output, particularly on reds.


    Quote Originally Posted by blue View Post
    Is the cooling in these pure diode modules for keeping stable wavelength or for the duty cycle? I thought the heatsinks are enough for these diodes and wavelength isn't such an issue as with DPSS ones.

    And yeah swamidog, I can cut the "feathers" but I don't like loosing power on that. Maybe I'll just find an inexpensive prism pair to use with my cheap chinese module and use those.

  9. #49
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    Quote Originally Posted by norty303 View Post
    It is possible to do a certain amount of beam cleaning on the multi mode Reds by simple masking. I added BlackTak on the cylinder lenses to remove the worst of the wings. 30 second cheap fix
    I need to try that.

  10. #50
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    Yeah, but isn't a heatsink good enough for a diode already?

    And again, doesnt masking a wide beam reduce brightness? How much? Seems like not so much if you guys are doing it.

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