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Thread: Combining Driect and DPSS Green

  1. #1
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    Default Combining Driect and DPSS Green

    I am planning to upgrade a green, DHOM laser in one projector to a Laserwave. I could add a 2W or a 4 W; they have the same foot print. But, I could also try my idea of a direct diode and a DPSS, PBS combined. I am wondering if this has been tried yet. I am also wondering if anyone has any suggestions on how much current to drive the green with. I have seen DTR's images, but these don't represent a long term functioning level. Also, I could run the green at anywhere from base plate temp to (-) extreme. Is there any experience with the effects of heat on output? These are too expensive to destructively test (intentionally).

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    Heya Eric, The datasheet says 1.7A max, DTR took one up to 3.5A without codding it .. maybe just ramp the current up 'till you get 1W output & keep it chilled to ~20C ? I don't have one yet, so just throwing ideas out there .....
    - unless you are planning to overdrive it for more power output, then I wouldn't hazard a guess .. like you said, too expensive to destructively test ..

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    Quote Originally Posted by planters View Post
    I am also wondering if anyone has any suggestions on how much current to drive the green with.
    Which model exactly?

    Quote Originally Posted by planters View Post
    Also, I could run the green at anywhere from base plate temp to (-) extreme. Is there any experience with the effects of heat on output? These are too expensive to destructively test (intentionally).
    Wavelength shift nm/K is low, ~0.025nm / k.
    A 40 degree temperature increase from R.T. incurs ~40% drop in output power.
    - There is no such word as "can't" -
    - 60% of the time it works every time -

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    These are the NDG 7475, 1W diodes that I'm considering correcting and then adding to the polarized 2W Laserwave.

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    you will have different modulation characteristics. you might notice some odd color shifts during intensity changes and you'll probably want to use a color correction board to align the rise and fall times.
    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.

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    Swami,
    Yes, I thought about this and actually this is what I am curious about. I assume that the color correction board is not as important for all diode projectors. So, if that is true then the green diode might tend to reduce some of the discrepancy that the DPSS adds. I am using a colol correction board already and so I can run the green diode thru the 4th, dark blue channel. What do you think

  7. #7
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    i don't have a color corrector in my all diode projector (i have one in my larger dpss projector). the diode response is linear enough that it's no issue. the trick is to spend a little time with the grey circle test pattern and the bias controls on the flexmods.

    i have a small amount of constant glow out of my projector. it's not much and i could remove it if i used diode drivers with beam suppression.

    i took my diode projector to a friend's house last weekend and ran some of my shows through it. he's a gas head and used to pcaom blanking. he was absolutely blown away.

    it didn't hurt that my projector is roughly an 8" cube and can be carried in one hand.

    Click image for larger version. 

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    Quote Originally Posted by planters View Post
    Swami,
    Yes, I thought about this and actually this is what I am curious about. I assume that the color correction board is not as important for all diode projectors. So, if that is true then the green diode might tend to reduce some of the discrepancy that the DPSS adds. I am using a colol correction board already and so I can run the green diode thru the 4th, dark blue channel. What do you think
    Last edited by swamidog; 06-26-2014 at 10:09.
    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.

  8. #8
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    OK, I was reading in another thread about a new Kvant projector and the argument settled (again) on the problems with the 520nm based yellows. For this reason, I am going to go ahead with this. I think a dual band green may produce colors that just aren't generated with each of two wavelength alone. My favorite colors are never the primary ones, but the orange ,yellow,cyan etc. Based on Danielbrigs statement, I will also pick up a less expensive low power green diode to perform some temperature experiments with.

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    Not that I am an expert, I think colour correction boards are a must. It has made such a massive difference to my machine.
    In quick show if you select a circle and then cycle the colour thru it you can see the intensity remain a lot more constant .

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    i wonder how much of the "issue" is with the 520 green and how much of it is related to 637 read. try matching a 520 diode to 650-660 red and see what happens.

    Quote Originally Posted by planters View Post
    OK, I was reading in another thread about a new Kvant projector and the argument settled (again) on the problems with the 520nm based yellows. For this reason, I am going to go ahead with this. I think a dual band green may produce colors that just aren't generated with each of two wavelength alone. My favorite colors are never the primary ones, but the orange ,yellow,cyan etc. Based on Danielbrigs statement, I will also pick up a less expensive low power green diode to perform some temperature experiments with.
    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.

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