1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Calculating the heating effect of a Class IV laser

  1. Jul 5, 2010 #1
    Hi guys,

    I am of a Mechanical Engineering background, however my dissertation has a largely optics based focus, and I am struggling with understanding the heating effect of a Laser.

    I will be using various wavelength ND:Yag lasers, and will be focussing them onto a target material, which I have not yet decided upon. I need to be able to calculate the heating effect of the laser on this material.

    For example, if I pulse the laser constantly for 2 seconds, what will be the temperature increase of the material?

    For arguement's sake, we could consider the laser to be of these specifications:

    Dimensions
    Laser transmitter 325 x 201 x 119 mm
    Laser receiver 105 x 77 x 23 mm
    Mass
    Laser transmitter < 7.5 kg
    Laser receiver < 0.5 kg
    Aperture
    10 mm
    Beam Divergence
    Tactical @ 1.06 μm < 1 mRad
    Output Energy
    < 300 mJ @ 1.06 μm
    < 90 mJ @ 1.57 μm
    Repetition Rate
    20 Hz (on both wavelengths)
    Average Power
    < 325 W


    Thank you very much for your input.

    Alex
     
  2. jcsd
  3. Jul 5, 2010 #2

    Andy Resnick

    User Avatar
    Science Advisor
    Education Advisor

    The temperature increase will be driven by the amount of absorbed energy, nothing more- unless the pulse is of ~fs duration.
     
  4. Jul 6, 2010 #3
    thank you for your reply. I am ultimately looking for the surface temperature within the beam of the laser. As surely the part inside the beam will become much hotter than that outside? also- do you have any kind of equations that would be appropriate?
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook