Page 1 of 2 12 LastLast
Results 1 to 10 of 18

Thread: PBS confusion

  1. #1
    Join Date
    Jul 2008
    Location
    Kent, UK
    Posts
    34

    Question PBS confusion

    I'm a bit confused when you combine 2 beams using a PBS cube the beam that emerges is the total of the beams you put in isn't it ? (Or is it an average or some other figure due to refraction).
    My friends say I'm mad , I suppose they're not wrong !

  2. #2
    Join Date
    Jul 2007
    Location
    Knoxville, TN, USA
    Posts
    3,154

    Default

    Unfortunately, you'll probably lose at least a little bit with EVERY optic you use, be it mirrors (including the scanners), cubes, and dichro filters.

    Because of this, the total power coming out of the PBS cube will probably be slighly less than the total of the separate lasers added together.
    The trick, it would seem, is to minimize that loss at every step of the way.
    So, if you hold your mouth just right while aligning the various optics, eveything should work out with minimal losses - until you decide to change something and have to do it all over again!!
    RR

    Metrologic HeNe 3.3mw Modulated laser, 2 Radio Shack motors, and a broken mirror.
    1979.
    Sweet.....

  3. #3
    soforene's Avatar
    soforene is offline The Troll formerly known as Herbert Von Poople-Futtocks
    Join Date
    Aug 2007
    Posts
    2,928

    Default

    Quote Originally Posted by Stuka View Post
    ...So, if you hold your mouth just right while aligning the various optics, eveything should work out with minimal losses....
    You just know he's gonna ask how to hold it.





  4. #4
    Join Date
    Jul 2007
    Location
    Knoxville, TN, USA
    Posts
    3,154

    Default

    That would probably do it!!
    RR

    Metrologic HeNe 3.3mw Modulated laser, 2 Radio Shack motors, and a broken mirror.
    1979.
    Sweet.....

  5. #5
    Join Date
    Nov 2007
    Location
    Sydney, Australia
    Posts
    602

    Default

    So how do you align the optics when it requires both hands to hold you're mouth just right
    RTI Piko RGB 4 Projector
    CT6215 Scanners & CT 671 Amps; CT6210 & Medialas Microamps.
    RGBLaser Systems 6000mW RGB Module - 638nm/445nm/532
    LD2000 Pro + QM2000.net + Beyond
    Etherdream + LSX

    Old Projector Build


  6. #6
    Join Date
    Jul 2007
    Location
    Knoxville, TN, USA
    Posts
    3,154

    Default

    LOTS of practice !!

    All kidding aside -

    Work with one optic at a time to get the best beam power out of it, then move to the next one. It may take a while to get everything aligned the first time around, but once it's done properly, periodic minor adjustments should be all that is needed (which is why you want to use adjustable mounts for all your optics).

    And until you've done this a time or two, or ANYTIME there's a question where the beams might be going - wear laser safety goggles!!
    RR

    Metrologic HeNe 3.3mw Modulated laser, 2 Radio Shack motors, and a broken mirror.
    1979.
    Sweet.....

  7. #7
    Join Date
    Oct 2006
    Location
    Central Florida
    Posts
    7,067

    Wink

    Quote Originally Posted by Stuka View Post
    ANYTIME there's a question where the beams might be going - wear laser safety goggles!!
    Because you can't throw your hands up to block the beam if you are holding your mouth correctly.
    Love, peace, and grease,

    allthat... aka: aaron@pangolin

  8. #8
    Join Date
    Jul 2008
    Location
    Kent, UK
    Posts
    34

    Red face An experiment

    Has any one got a PBS cube, a laser power meter, some different powered modules and some free time? I was thinking you try different combinations of input (to the cube) and measure the output, what percentage of the input will be the output be ?
    My friends say I'm mad , I suppose they're not wrong !

  9. #9
    Join Date
    Oct 2006
    Location
    Central Florida
    Posts
    7,067

    Lightbulb

    rob (stanwax) has done, from what I understand, some extensive "research" on this subject. Rob...?

  10. #10
    Join Date
    Jul 2007
    Location
    Knoxville, TN, USA
    Posts
    3,154

    Default

    Hooking up with some of the local fellows is a good suggestion.!

    I don't thing there's going to be any "standard" configuration you can test for a catch-all guideline, since there's a LOT of variation in optics. You'll need to test the specific lasers you plan on using with specific PBS cubes designed for their wavelengths.

    Also, my (limited) understanding of the theory behind the use of PBS cubes is you can't take just any 2 lasers of the same wavelength for it to work - they have to have very specific polarized output beam characteristics. The details of THAT, unfortunately, I can't be much help with, but hopefully some of the more knowledgeable folks will chime in with some more info...
    RR

    Metrologic HeNe 3.3mw Modulated laser, 2 Radio Shack motors, and a broken mirror.
    1979.
    Sweet.....

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •