Laser or LED

Discussion in 'General Electronics Chat' started by Paulquinn, Aug 28, 2013.

  1. Paulquinn

    Thread Starter New Member

    Aug 28, 2013
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    Hey guys. I'm fairly new to electronics
    Just getting my feet wet. I am attempting my first project and bought a
    980nm laser module online. My question is, how can I be sure it is in fact
    A laser and not just an LED? Because its 980nm I can only see it
    Through my camera. But there is no beam when I pass it through smoke
    Which got me thinking that it might just be an LED
    Any help would be great thanks.
     
  2. pwdixon

    Member

    Oct 11, 2012
    488
    56
    If you can't see the light normally why would you think you'd be able to see a beam in smoke? Smoke isn't going to shift the wavelength into the visible I'm afraid. A camera has a wider range of acceptable wavelengths and in fact translates the invisible to visible at these wavelengths so I'd imagine you might see a beam through the camera in smoke.
     
  3. snowdrifter

    Member

    Aug 13, 2013
    43
    1
    980 nm is well into the IR spectrum. As Dixon said regardless of whether you shine it through smoke or not, it will only cause the light to disperse off of whatever particles are in the air, but it still won't be able to see it with your naked eye.

    As for finding out if it's a laser vs. and LED, you could always contact the seller to be sure. Or shine it on an object and look through a camera(some work better than others for this).


    Could you post a picture of what you got?
     
  4. #12

    Expert

    Nov 30, 2010
    16,261
    6,774
    Assuming you can detect the beam with something...an LED would be useless at 10 meters, but a laser would still appear to be a good, solid, illumination spot.
     
  5. wayneh

    Expert

    Sep 9, 2010
    12,100
    3,034
    And in case it isn't obvious, don't aim the laser directly into your camera :eek:, but onto something that would show a reflected and diffused IR "spot". I assume white paper would work as it does for visible light.
     
  6. vpoko

    Member

    Jan 5, 2012
    258
    47
    An IR LED will also act as an IR detector. If you hook it up to your DMM, you'll get a voltage when you shine an IR light on it (like from a remote control, or even a regular light bulb, which puts some of its energy out as IR). I don't believe an IR laser would do this.

    Also, if playing with lasers, get appropriate goggles. With an IR laser, you could damage your vision and not even realize it right away.
     
  7. Shagas

    Active Member

    May 13, 2013
    802
    74
    Too many video games :D

    As mentioned above , point it at a wall or something at 10-15 meters distance and take your smartphone and go up to where the dot should be and see if you can see it through the camera . If yes then it's a laser .
    Also .... DON'T point that thing in your eyes. Even if you can't see the beam it can do serious damage if it enters the eye.

    Also , link the product that you got . I'm also waiting for a 980nm laser with TTL from ebay.

    Another thing ... Stick to the voltages specified in the datasheet (assuming that it's a module and not a naked laser diode ).
    Use fixed voltage regulators , or adjustable with a fixed calculated resistor . Never have a voltage regulator with an adjustable potentiometer powering things like lasers etc .
    I've burned over 100 euros worth of laser diodes that way . Pretty sad :(
     
  8. Paulquinn

    Thread Starter New Member

    Aug 28, 2013
    5
    0
    Ok need to clarify, I meant seeing the beam through smoke with my
    Camera. I realise you can't see it with naked eye no matter what.
    It is a "laser module" not a diode. I got it on eBay for $9.88mine has a yellow ttl lead. I'm just trying to make sure it's a laser not a led befor installing on my
    Project.
     
  9. wayneh

    Expert

    Sep 9, 2010
    12,100
    3,034
    I suppose it's worth pointing out that these two things are not mutually exclusive. It could be both an LED and a laser.
     
  10. Shagas

    Active Member

    May 13, 2013
    802
    74
    Yeah I think I have the same module arriving in a week.
    I'm pretty sure it's laser .
    I told you how you can test it. If you want to be extra sure test it at a bigger distance .
     
  11. Shagas

    Active Member

    May 13, 2013
    802
    74
    What do you mean ?
    Please elaborate
     
  12. Paulquinn

    Thread Starter New Member

    Aug 28, 2013
    5
    0
    Thanks lads ill try your suggestions.
     
  13. wayneh

    Expert

    Sep 9, 2010
    12,100
    3,034
    I'm just being a stickler for language. A laser diode is a diode that emits light. So it is, technically, a type of light emitting diode. That's all. The OP's question is like asking, "is this a wrench or a tool?". But we all understand what he meant.
     
  14. Shagas

    Active Member

    May 13, 2013
    802
    74
    Ok I see what you mean
     
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