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Thread: Pbs cube secrets

  1. #1
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    Lightbulb Pbs cube secrets

    Hi

    I haven't actually found too much info on the PBS CUBE in detail on this forum(Correct me if I'm wrong) So Id like to ask a question.

    I have recently got myself 2 1Watt 650nm labbies and I see the beam being a square shape or nearly square(Elongated)
    When putting them through a Polarising PBS Cube they form a cross like this +

    Anyway I went and did some more research on the Cubes and I tried searching this and it worked..."NON-Polarising PBS Cubes". Does this mean that I can mesh the beam properly And create a "REAL" luminosity from it in this kind of shape - ?

    The cross is just pathetic and pretty useless as far as I'm concerned for use with a RGB setup.

    Thanks I'd appreciate the info (Or a good price)
    Here is a Website http://www.crylight.com/Polarization...e-NPB-_58.html

    Peace,Respect

  2. #2
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    I'm probably wrong as I have very little knowledge in this area, but I think non polarized cubes can only be used to split a beam and can not be used to combine two beams.

  3. #3
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    Quote Originally Posted by laser_freak View Post
    I'm probably wrong as I have very little knowledge in this area, but I think non polarized cubes can only be used to split a beam and can not be used to combine two beams.
    Correct, it merely reflects half of the input beam at 90, no use at all for combining beams.
    http://img62.imageshack.us/img62/3985/laser.gif

    Doc's website

    The Health and Safety Act 1971

    Recklessly interfering with Darwins natural selection process, thereby extending the life cycle of dim-witted ignorami; thus perpetuating and magnifying the danger to us all, by enabling them to breed and walk amongst us, our children and loved ones.





  4. #4
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    so, to avoid the cross try to mount the second 650 90 degrees perpendicular to the first

    this way one beam will go into the cube like " | ", the other will go into the cube like " - " and they will both come out like " | "

  5. #5
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    Quote Originally Posted by LaNeK779 View Post
    so, to avoid the cross try to mount the second 650 90 degrees perpendicular to the first

    this way one beam will go into the cube like " | ", the other will go into the cube like " - " and they will both come out like " | "
    ? I'm confused how that would work. Can you please elaborate?

  6. #6
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    re-reading my post above, even i didn't make sense to myself

    instead of elaborating, i prefer to link yoy to this page, by this nice chap who does better than me
    http://www.laser-man.co.uk/2006/inde...d=68&Itemid=66
    the second photo is what i'm talking about
    Last edited by LaNeK779; 11-12-2010 at 01:45.

  7. #7
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    Quote Originally Posted by king4quarter View Post
    Histion.

    I have recently got myself 2 1Watt 650nm labbies and I see the beam being a square shape or nearly square(Elongated)
    When putting them through a Polarising PBS Cube they form a cross like this +

    Anyway I went and did some more research on the Cubes and I tried searching this and it worked..."NON-Polarising PBS Cubes". Does this mean that I can mesh the beam properly And create a "REAL" luminosity from it in this kind of shape - ?

    The cross is just pathetic and pretty useless as far as I'm concerned for use with a RGB setup.

    As doc said, a non polarizing beamsplitter will only reflect 50%, so if you use 2 x 1W you end up with 1W, so pretty useless.

    If you want to combine 2 beams without rotating the laser 90 degrees you can use a waveplate.

    this optic will turn wave 90 degrees without turning the beam 90 degrees and you end up with a beam similar as the first laser only double the power.

    http://store.laserextreme.nl/catalog...products_id/59

  8. #8
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    Ah, so I think you may have just answered one of my queries regarding uses for waveplates.

    Are you saying that if you have a diode that is polarized horizontally and a beam shape like ---- that you could use a waveplate and the shape would still be ---- but the polarization would be vertical?

    So this is a nice way of avoiding the + shape when using a cube? So you could run a waveplate, then cube, then correction optics/prisms and get a combined beam like -- instead of ---- ?

    Or you could knife edge and have less losses....?

  9. #9
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    Correct, waveplate changes polarity not beamshape.

    thats why all good companies uses waveplate.

    The 650mW 640nm modules I supply from livelasersystems even uses waveplates in these quads to get the best beamshape in the industry, and do not have to struggle with lowering or raising the beam hight.

  10. #10
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    Ok, so what are the losses associated with a moderately priced waveplate?
    And how much is a moderately priced waveplate?

    I'm seeing 2 sets of (2 diodes with a cube and waveplate) and then knife edged and then corrected.

    All we need now is a moderately priced 630-640nm diode with beam specs in the region of the 445's

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