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Thread: What Wavelength is Whitelight?

  1. #1
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    Default What Wavelength is Whitelight?

    Anybody know? Also on a relient 300m there is a little bit of beam shooting from the rear end of the tube. What percent is this to the actual output?

  2. #2

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    White is a combonation of multiple visable wavelengths. A melting pot by any other name. "Temperature in Kelvin" / "intensity in lumens"

    From my experience with lower power argons the HR mirror is around 99% reflective, so about 1 percent. Yadda would be able to explain in more detail.

    They dont call it a "cavity" for nothing

  3. #3
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    Hi, Jay, just FYI there is NO power loss due to the light escaping from
    the rear of the laser for all practical calculations. You can say 0 percent
    of the light escaping out of the rear is considered output.

    A better HR will make the laser more "efficient" allowing it to generate higher
    intracavity power levels at lower input current, but current isn't strictly
    a good measure of what kills the laser... a more accurate statement is
    inadequate heat dissipation as a relation to intracavity laser power kills
    lasers.... So you wouldn't gain anything unless you upgrade the cooling.
    But then, if you upgraded the cooling, you could safely turn the current up.

    Keep in mind that on the Reliant series, they already have some seriously
    nice HR/OC optics hard sealed on there... Thats why you can run them
    at 400mW (Albeit at reduced lifespan of the head)...

    If you had bought a commercial Reliant, WC or D series, etc... they would
    have put some high temp black silicone goop on the end...

    "True" white light is a broad spectrum which emits at almost all visible
    frequencies...

    In laser parlance, it just means you have at least 1 red, 1 green and 1 blue...
    and by combining the values you can make at least a close approximation
    of most colors (albeit at reduced gamut)...

    On an 8 channel PCAOM using a whitelight ArKr laser... you'll generally
    see the two reds, a yellow, two greens, cyan, blue and violet... The
    Red'n yellow you tend not to see until the power is turned up a bit...
    Some ArKr fills have a stronger 2nd blue so they recrystal the driver for the
    2nd blue in place of violet.

  4. #4
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    Default

    Well my PCAOM is set for 2 Reds, 3 Greens, 3 Blues. I wanted to know the % of power coming from the HR so I could use it as a measuring point, when doing shows. I wish that the PCAOM didn't waste so much of the beam though. The waste beam looks so much brighter, then the usable beam. The tube is a reliant WC, with a AR/KR fill, and I have an extra tube. The hours meter only has 1258.6 on it. So, it should be a while until I have to use it. I'd like to figure out if I could find a dead reliant 300, and install the spare tube, combine it with what I have now, and get double the output power. Although, this might not be possible.

  5. #5
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    Hi Jay

    Congrats on the Reliant...nice laser dude

    I miss my old Lexel 88
    Atho multiline.,..just no RED
    But I dont miss the hook-ups!!!

    Still ., Nice kill dude ...
    I dont see any problem putting the other tube into a dead unit..
    Be nice to have as a back-up in case the other should fail..

    *^_^*
    "My signature has been taken, so Insert another here"
    http://repairfaq.ece.drexel.edu/sam/laserfaq.htm
    *^_^* aka PhiloUHF

  6. #6
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    Nice, You got a 300WC then? Crazy! I love those things...

    if your other tube is the same type, then the PSU for the 1000D/M is the
    same as the 300WC...

    For measurement, there's no standard except measuring the output and
    measuring the waste... the percent will be linear...

    On the PCAOM, the bragg angle will determine your efficiency, also where
    you're hitting the crystal and the crystal size also plays an important role...
    The RF crystals inside your driver also needs to be perfectly matched to
    the wavelengths you're tuning for... With improper tuning, you'll see
    only 60-80% transmissiveness... with everything dead on, you can
    see up to 95% efficiency... If you're losing more than 50% then I would
    check polarization of your source laser...

    To calibrate (you'll need a power meter for this) turn on all of your laser lines...
    Measure the input voltage and make sure that it's exactly 5V... to make
    sure you're telling it to transmit as much as possible... then measure the
    power output vs waste beam... (Note you can do this at lower power levels)
    Then adjust X, Y, Z and yaw and roll angle... (Roll is used to align polarization)
    it looks like you're going through a bounce mirror between the laser and
    PCAOM so unless path is completely flat, the bounce may rotate the
    polarization slightly. I think I noted that your bragg mount doesn't seem to have
    a roll adjustment...

    Sanity check, note that in normal operation (i.e. where you're not scanning
    white) you're of course not going to transmit anything you don't want..
    Most people take the 0th order waste beam to drive the effects table.

  7. #7
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    Thats not a bad idea. I have been working on a beam table, and to collect the waste off the PCAOM is something I would not have thought of. This would mean a slight modification to the orginal projector, but not a problem. I'll take some more pictures of the equipment, and the tube. I'll post them to gallery tonight.

  8. #8
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    Rockin' we like pics You should make a post detailing your system...

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