Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Measuring laser output temperature

  1. Nov 10, 2010 #1

    This is my first post on this forum, just joined. I recently purched the S3 Spyder III Arctic portable 1W laser from wickedlasers. I bought it to try and make some cool photographs and photoshop them. After testing the device (glad I bought safety goggles with it) I was wondering how hot the laserdot actually gets. Short of buying an expensive thermometer is there any way to guestimate this? I've tried to set fire to a match (used one) and a candle wick that also has burned before. I'm not sure but I guess a catalyst like an actual flame is necessary to ignite those materials no matter how hot you get them to be.
    Does anyone have an easy way to determine what temperatures could be reached with this laser? It operates on an average of 900mW and at a wavelenght of 445nm.

    I'm not versed at all in physics, save from the little I remember from high school so I'm sorry if it's a stupid question.
  2. jcsd
  3. Nov 10, 2010 #2


    User Avatar
    Science Advisor

    No, it isn't a stupid question, but it is not an easy one to answer.

    1 watt isn't much power and even if you assumed it was all heat, it couldn't do much heating.

    If you concentrated all the power into a very small dot and shone this on a poor heat conductor, you might get some local scorching.

    If the spot was 1 square mm and the depth of heating was 0.1 mm and you knew the specific heat of the target material, you might be able to estimate the heating with 1 watt.

    I can't see you cutting up razor blades with it.
    I saw a video of someone cutting the metal blade of a tomahawk with a laser, but that was a serious laser.

    It might have enough power to pop a balloon. Maybe enough to light a match.

    Plenty of power to ruin your retina, though, so keep those goggles on. Even with the goggles, don't look directly at the laser.

    You can get non-contact thermometers, but they take an average of everything in their field of view, so the hot spot from the laser would get averaged with a lot of stuff at room temperature.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Measuring laser output temperature