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Thread: ~455nm laser diode - OSRAM PLT4

  1. #1
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    Default ~455nm laser diode - OSRAM PLT4

    I'm never quite sure if it's ok to cross-post like this? I thought this might be of interest to some of the members here, and it was thanks to a great member here on PL that I was able to get the diode mounted and running

    The nutshell - I have what I believe to be an OSRAM PLT4 diode (harvested from a Microvision pico projector). Ran it in a module focussed for the first time today. Using some diffraction grating math, it appears to be roughly 457nm. While I'm not willing to bet my life on that wavelength being correct in absolute value terms, what WAS fairly plain and clear, was that the wavelength (whatever it is) is about 10nm higher than a typical A130 diode. Plus, it's single mode

    Neat stuff!

    (sorry if this is an etiquette faux-pas)
    http://laserpointerforums.com/f40/co...gth-65070.html

  2. #2
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    I have a spectrometer now, If anyone cares to send me one for a quick test, I'll send it back and post the findings. 457 is an ideal color. Any news on power output?

  3. #3
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    Very kind of you to offer. I may take advantage of that offer once I'm done playing with my new toy

    Side note - what kind of investment is necessary to get into a working (used) spectrometer ?

  4. #4
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    Quote Originally Posted by rhd View Post

    Side note - what kind of investment is necessary to get into a working (used) spectrometer ?
    I'm doing some projector work in trade for it but I think you can find a "starter" spectrometer on ebay for $400 to $1K. I got myself a RedTide USB650, It's nice!

  5. #5
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    I have one of the science-surplus spectrometers. Seems to be fairly accurate.

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  6. #6
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    The whole projector assembly looks to be interesting enough:

    http://laserpointerforums.com/f51/ha...een-64072.html

    Some 642, 455 and a directly doubled 532 complete with pre-aligned dichros and collimators -- if anything, this could be an out-of-the-box white light brick.

    Basically, I wonder what it would do if you could just rip off the MEMS assembly and project a fully white image -- my gut instinct tells me it will give you a (time multiplexed) white beam output.

    The 642 and 455 are pretty straightforward to get running, but I guess it's trial and error to get the 532 up and lasing. Once you've got that done... a threesome of Flexmods and a pair of scanners and you're ready for the ILDA test frame, I guess?

  7. #7
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    this could be an out-of-the-box white light brick....I guess
    No, not really:

    This brick is designed to illuminate a dlp uniformly.
    That's an entire ballpark than creating a collinear laser beam focused @ infinity.

    If you try to collimate this brick you'll probably find out that you can't focus all colors at the same distance, because of their difference in wavelength.
    An achromat might work, but maybe beams might be focused at different distances to achieve uniform illumination of the dlp.
    Also the farfield alignment would be übercrappy because it's of no importance in a pico projector.

    On the bright side, the diodes might have some beamshaping optics in front of them !

  8. #8
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    Quote Originally Posted by rhd View Post
    Very kind of you to offer. I may take advantage of that offer once I'm done playing with my new toy

    Side note - what kind of investment is necessary to get into a working (used) spectrometer ?
    Or you can look up Zoof's post on this very forum and buy a 2 dollar diffraction grating and use his excellent Excel sheet to do the calculations. If you can use a tape measure you can define the wavelength pretty accurate and cost you very little !
    I didn't fail !
    I just found out 10,000 ways that didn't work.

  9. #9
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    Quote Originally Posted by -bart- View Post
    No, not really:

    This brick is designed to illuminate a dlp uniformly.
    That's an entire ballpark than creating a collinear laser beam focused @ infinity.!
    I could be wrong but I am pretty sure that is not a DLP. It is a flying spot X resonant Y scanned mems mirror. They also quote 'infinite' focus as a selling point.
    I am pretty sure that it is a collinear, collimated rgb beam. I am with Stoney3K on this one, I have been thinking the same thing for a long time.

    The tough part is going to be getting the green lasing. It takes a lot of control to do it's thing, you can't just give it juice and expect green out the other side.
    That is something that should be thoroughly scoped out while running if you want to have any hope of getting green.
    Here is some info on it.
    http://www.corning.com/docs/corporat.../NTR102412.pdf

    Chad


    When the going gets weird, the weird turn pro.


  10. #10
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    Quote Originally Posted by chad View Post
    I could be wrong but I am pretty sure that is not a DLP. It is a flying spot X resonant Y scanned mems mirror. They also quote 'infinite' focus as a selling point.
    I am pretty sure that it is a collinear, collimated rgb beam. I am with Stoney3K on this one, I have been thinking the same thing for a long time.

    The tough part is going to be getting the green lasing. It takes a lot of control to do it's thing, you can't just give it juice and expect green out the other side.
    That is something that should be thoroughly scoped out while running if you want to have any hope of getting green.
    Here is some info on it.
    http://www.corning.com/docs/corporat.../NTR102412.pdf

    Chad
    From what I read from there, most of the challenge is in temperature stabilization of the whole system. The red and blue are already worth more than the entire pico-projector retail, and you don't have to align the R and B with respect to each other.

    Does anyone have a working pico-projector and in the position to reverse engineer the current control on the green diode? If we can fire up a working unit and scope all of the wires coming in/going out of the green module, we may be able to learn some more from it.

    The fact that it's a scanning MEMS makes me think there is no time multiplexing going on between the colours, instead, all colours may be driven simultaneously. Projecting a fully white image would mean the whole unit will go flat out CW on all three colours.

    Would it be possible to run the unit vanilla (as a video projector) with the cover off the optical path?

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