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Thread: optics

  1. #1
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    Default optics

    anyone know what optic i need to turn a 650nm beam 90 degrees i know i can do it with two mirrors but i cant make one thats very stable i am just hoping theres somthing out there ready made

  2. #2
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    Cool

    Turn the beam 90 degrees? You can do that with a single bounce mirror set at a 45 degree angle to the incident beam.

    Or do you mean rotate the polarization angle by 90 degrees? (And in that case, why not rotate the diode?)

    Adam

  3. #3
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    Default optics

    i wanted to turn 90 deg to go through a pbs cant turn the diodes because they are being knife edged past mirrors i want to combine six but want to line them up like a the hash # sign in a 5mm x 6mm area ,random polarized output from cube i dont want to use a 3x collimator after dont want the bad divergence want to try and get as much power as possible in as small area as possible and not have any extra optics

  4. #4
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    Default

    Hi

    You need a half wave plate. See here...

    http://en.wikipedia.org/wiki/Wave_plate

    They're pretty expensive though and you need to get one for the correct wavelength of laser your using. Edmund Optics, Newport, Melles Griot all sell them, just go to the relevant sites and do a search.

    Cheers

    Jem
    Quote: "There is a theory which states that if ever, for any reason, anyone discovers what exactly the Universe is for and why it is here it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another that states that this has already happened.... Douglas Adams 1952 - 2001

  5. #5
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    Default

    You're going to have some power loss through that 1/2 wave plate. It would be better to rotate the diode in it's mount. You can still use the knife-edge mirror trick to stack the beams like you want.

    Introducing an optic just to rotate the polarization angle wastes power and will cost you a good bit of extra cash.

    Adam

  6. #6
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    Default

    Quote Originally Posted by buffo View Post
    Introducing an optic just to rotate the polarization angle wastes power and will cost you a good bit of extra cash.
    Sugar and water will do the job for cheap. Let's not get hung up on solid state physics just because it's 'hip' now. There's plenty with fun stuff going on in the liquid and gaseous phase as well.


    Losses, well... that's another story...

  7. #7
    mixedgas's Avatar
    mixedgas is online now Creaky Old Award Winning Bastard Technologist
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    Default

    Edmund optics is selling 2" x 2" plastic 1/2 wave plate, its lossey, but it will let him get going without having to scrap 3 old 1980s vintage laser disk players for good quality red waveplates and PBSs
    hint, hint.

    Steve roberts

  8. #8
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    Default

    sorry to semi hijack the thread but it seemed like a good place to ask the question...

    I have a few waveplates kicking around that i'm not sure what wavelength they were designed for. Is there a quick and dirty method to determine the correct wavelength the waveplate was designed for ?

    Jem
    Quote: "There is a theory which states that if ever, for any reason, anyone discovers what exactly the Universe is for and why it is here it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another that states that this has already happened.... Douglas Adams 1952 - 2001

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