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Diode Laser

Discussion in 'Electronic Design' started by Jon Slaughter, Mar 9, 2010.

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  1. What does a diode laser module add to a diode laser? A voltage regulator or
    current limiter?
     
  2. So when exact intensity control is not needed one can simply use a resistor
    a.k.a. the basic method used for current limiting led's?
     
  3. nospam

    nospam Guest

    Lol.

    Last one I did a driver for datasheet rated maximum power 10mW, absolute
    maximum power 11mW for 10uS.
     
  4. Jamie

    Jamie Guest

    Current regulation is very important.
     
  5. Joerg

    Joerg Guest


    Not temperature control itself but they contain a thermistor, typically
    a 10k version.
     
  6. Joerg

    Joerg Guest

    Oh yeah. I prefer current sources as well. For hobbyists the LM317
    rigged as a current source should do quite well. It's a well-behaved
    regulator.
    Although I often couldn't live with the large capacitance. So far I have
    not destroyed one, and I've worked with quite a few including some in
    the four-digit a piece price range. As long as the current source can
    never ever spike and there's a reverse diode protection most situations
    are ok.
     
  7. How do I determine the working current from the datasheet? I have an OPV322
    that I ran from about 3mA to 5mA. The datasheet says the max is 12mA(Maximum
    Forward Peak Continuous Current) and the threshold is 3mA. It says the min
    total power output is 1.5mW at If=7mA.

    So I take it that the operating range is 3mA to 12mA with average of 7mA?

    What I don't understand is that mouser listed this as a 5mW part and on the
    datasheet it has the warning box which says 10mW and the spec says 1.5mW.

    In any case it does work but I would like to get about 80-90% of the maximum
    which I'm figuring is about 10mA.
     
  8. JosephKK

    JosephKK Guest

    Most often, an optical interface with a connector.
     
  9. Just playing around with some night vision stuff. I got it to 10mA and it
    didn't burn up so I figure that is probably the max I'll take it. It's
    nothing serious. Main thing I need to deal with is the optics. Essentially
    trying to build an infrared flashlight to replace one that used an IR led
    and was terrible. Nothing serious though and just for fun. Main thing I
    gotta worry about is not doing self-lasik ;)

    Basically 6V's got me 1.7V across the diode at 10mA(had 430Ohms in series).
    Thats 17mW which far exceeds the spec if they are 5mW's unless I'm missing
    something.
     
  10. You are missing that the spec is for the *optical power output*, but you
    are measuring the power input!

    The failure mechanism for laser diodes is usually excessive optical
    output power, so it is this that you must constrain,

    But your 10mA is just about within the 12mA @25'C rating, so that is why
    it has not blown up.

    Careful - laser diodes are normally very sensitive to even very short
    overloads (microseconds-nanoseconds). You may already have blown it
    up. It would still take current but the output will be down to almost
    nothing (it turns into a weak LED). You need to be careful with ESD.

    Having said that this one accepts a 48mA 1us pulse so it is not as
    sensitive as some.
     
  11. Joerg

    Joerg Guest

    They can also be killed if they are run borderline and then some
    reflection changes in the optical path, meaning outside the part. Except
    that you won't hear a PHUT sound, it just quietly signs off for good.
     
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