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Thread: Light beam intensity

  1. #1 Light beam intensity 
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    I understand why lasers are valuable for a variety of experiments, but for the purpose of cutting things, why is it more effective than merely precisely focusing a beam of light? A know that normal light is out of phase with itself, but this cannot cause a reduction in immediate intensity, can it?


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    Forum Radioactive Isotope MagiMaster's Avatar
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    This is a wild guess, but I'd bet that the phase does matter. Just like cracking a wine glass with sound, you need a steady note. White noise won't work.

    Now, it may just be that it's easier to make a high intensity laser compared to focusing equally high intensity light.


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  4. #3  
    Forum Masters Degree organic god's Avatar
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    in the laser the gain medium can be any phase therefore you are correct that the phase does not matter.

    In terms of focusing a beam of light.
    A laser is a lot more tightly focused than the beam of light due to the high convergence of it's wavelengths compare this to light which has a high divergence and the reduction in intensity due to this divergence is large
    everything is mathematical.
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  5. #4  
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    Quote Originally Posted by MagiMaster
    This is a wild guess, but I'd bet that the phase does matter. Just like cracking a wine glass with sound, you need a steady note. White noise won't work.

    Now, it may just be that it's easier to make a high intensity laser compared to focusing equally high intensity light.
    Most heavy cutting lasers are white or blue white.

    Sincerely,


    William McCormick
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  6. #5  
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    I noticed that even if you use high end optics to concentrate a beam of light into a certain area, you will still see it outside of that area. Is this the divergence you were talking about? Could it be that because a laser has all of its photons in phase, they can only equally positively reinforce each other in the same direction, while a normal light beam is able to greatly vary and differ its probability wave allowing for the light to have a needed chance of consistently reaching outside of your declared region?
    Of all the wonders in the universe, none is likely more fascinating and complicated than human nature.

    "Two things are infinite: the universe and human stupidity; and I'm not sure about the universe."

    "Great spirits have always found violent opposition from mediocrities. The latter cannot understand it when a man does not thoughtlessly submit to hereditary prejudices but honestly and courageously uses his intelligence"

    -Einstein

    http://boinc.berkeley.edu/download.php

    Use your computing strength for science!
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