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Thread: lowest useful output power?

  1. #11
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    Quote Originally Posted by flecom View Post
    I was just wondering with all the drama about the inevitability of these going into pointers, whats the lowest output power you can realistically get out of these diodes, can you run them at like 5~10mW and still get lasing?

    I was thinking of putting one of these in my stand-alone lumia projector but 1W would be waaayyyyyy too much blue...
    I just tested a 2 Watt 808nm LD and I can get it to lase at 1mW @~360mA...
    so the low end of my LD can me adjusted quite low...
    I can't see why the 445nm LD could not go as low...

    Jerry
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  2. #12
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    Jerry, sure its still coherent lasing, and not spontaneous emission from a very small emitter, which collimates well enough to look like lasing?

    probably hard to tell apart, for IR lasers. not sure if its easy to see the specle of coherent light in a IR-cam or the like..

    anyway: using an aperture near the lens will reduce power and enhance beam-quality..

    manuel

  3. #13
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    I've just set one up on 3.5W TEC, it lases down to less than 5mW.
    http://img62.imageshack.us/img62/3985/laser.gif

    Doc's website

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  4. #14
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    Thank you for posting your results. That is good news.

  5. #15
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    Quote Originally Posted by Krutz View Post
    Jerry, sure its still coherent lasing, and not spontaneous emission from a very small emitter, which collimates well enough to look like lasing?

    probably hard to tell apart, for IR lasers. not sure if its easy to see the specle of coherent light in a IR-cam or the like..

    anyway: using an aperture near the lens will reduce power and enhance beam-quality..

    manuel
    I used an IR indicator card to see the beam profile... the Thermopile head
    was about 18"-20" away from the LD lens...
    At that low power I could see that perhaps not all the multimode emitters
    were lasing exactly at the same time.....
    As I increased power the profile changed as more emitters started Lasing...
    At least this is what I think is happening... I normally run this Laser at a
    much higher output..

    Jerry
    See the LaserBee II and all other LaserBee LPM products here....
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  6. #16
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    *bump* any news of that? Would be PWM'ing the Dioden an option for 5-15mW?

  7. #17
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    Default Low power

    Use a neutral density filter on the output to reduce the power to whatever you want. If it comes on at 100mw attenuate it 100 times to make it 1mw. Thus 1 watt would then be 100mw so you'd have 1-100mw laser. OR....buy a 50mw 445 diode. They are not that expensive and they have a great beam profile.

  8. #18
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    Quote Originally Posted by kecked View Post
    OR....buy a 50mw 445 diode. They are not that expensive and they have a great beam profile.
    like $20~30 not expensive?

  9. #19
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    Or more like the price of a whole A130?

  10. #20
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    Like what kecked said, but with a twist.
    filter is better, but you can use a piece of glass and
    keep what bounces off. is about 10% or so?
    (may get 2 beams because of reflections on both sides.)
    cheap and stable.

    OR..

    use a piece of glass, keep the main beam, use the reflected beam to
    sense the power level, to automatically feed into the driver.
    (IE using real optical feedback)
    Haven't seen any DIY or one's for sale around here that can do that though.
    But not too hard to build.

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