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Homework Help: Laser burning power

  1. Jun 30, 2012 #1
    1. The problem statement, all variables and given/known data
    I would like to learn how to calculate whether a laser can burn through a material, or not. For example right now I need to calculate whether a laser from a DVD burner (which supposedly is max. 400 mW strong) can burn through steel.

    2. Relevant equations
    I can imagine that I need to know the power of the laser in mW, the wavelength of the light it is emitting, the melting and boiling temperature and thermal conductivity of the material it is shining on. Also, I guess some optical properties will be important but I don't know which.

    3. The attempt at a solution
    So far I gathered data on thermal properties of steel and other materials and power and wavelength of the laser.

    Thank you very much for your help
  2. jcsd
  3. Jun 30, 2012 #2
    No way 400mW can burn steel lol!
    All I can give you is experience. I had a 2W 445nm blue laser pointer focused into a 2*2mm dot. It could only burn black paper and black very thin plastic never achieving ignition.
    Laser's to cut metal are in the order of kilowatts, I remember seeing a CO2 laser with 50W that was used just to engrave corks for wine.
    With small diodes you can't do much, and even these cost around 100USD.

    There are allot of variables, but I hope someone can give you a scientific answer.
  4. Jul 1, 2012 #3
    Thank you very much for your help.
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