Fast Response LASER

Discussion in 'The Projects Forum' started by rueffy, Oct 16, 2013.

  1. rueffy

    Thread Starter Member

    Jun 29, 2013

    Anyone know of a LASER pointer or similar device that is capable of turning on and off at a rate of 10kHz plus. The LASER beam will be subject to PWM for the purposes of audio transmission through free space.

    Turns out e-bay LASER's aren't up to the task.

  2. richard.cs


    Mar 3, 2012
    I don't know of any diode lasers part numbers although I'm sure lasers that do what you want exist - have you tried buying them from places that publish accurate datasheets? I'd expect that information to be included.

    Were you using just a laser diode or an ebay laser module that included a bunch of drive electronics? You really want to drive the diode directly.

    Don't dismiss the option of running the laser CW and modulating with an LCD, moving mirror, etc
    rueffy likes this.
  3. Sensacell

    Senior Member

    Jun 19, 2012
    I believe the lasers themselves are fast enough, it's the DRIVER circuits that are slow.
    Maybe you could replace the driver circuit.
    rueffy likes this.
  4. Shagas

    Active Member

    May 13, 2013
    To OP:

    What you are looking for is a laser with TTL input.
    The driver you have has only two wires . You need one with three.
    A third yellow wire to which you will feed your pwm .
    Try searching ebay for something like : Laser module with TTL , or Laser TTL
    Or constant current driver with TTL , there are plenty available...

    If you want a laser pointer to do this then you will have to install the driver yourself .
    I doubt you will find (i'm sure you won't) a laser pointer with TTL , but a whole module(driver+laserdiode+ optics) you can find plenty. Then you can pick out a cylindrical housing for the module and your 10khz circuitry+switch+battery.
    Last edited: Oct 16, 2013
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  5. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    Ebay laser modules are VERY cheap and come as just the laser diode and focuser lens/brass housing, and two wires.

    You can modulate them just like a LED, at 10kHz or 100kHz no problem.
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  6. IC-Man

    New Member

    Jan 3, 2012
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  7. rueffy

    Thread Starter Member

    Jun 29, 2013
    Sorry I never got back to you guys on this thread, a LASER dot diode module was the way to go, I tried a LASER diode but it came with the collimating lens separate, a real pain to try and position correctly, the dot module was all ready to go, just needed to design a driver circuit around it.

    Thank you to all those that helped contribute to the development of my circuit. The project is now fully functional and I've made a video as part of my presentation to a class, the video shows the system in operation with a full description of signal flow etc.