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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:

    Laser transmitter 325 x 201 x 119 mm
    Laser receiver 105 x 77 x 23 mm
    Laser transmitter < 7.5 kg
    Laser receiver < 0.5 kg
    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.

  2. jcsd
  3. Jul 5, 2010 #2

    Andy Resnick

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    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?
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