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I Can a circularly Polarized Laser impart momentum to air?

  1. Nov 13, 2016 #1
    Does a circularly polarized laser beam, (say, 1 watt or so at visible wavelengths), impart linear or rotational momentum to air molecules.??
    I'm not talking of ionization of air....which I know it doesn't, ....but rather momentum, in particular due to its Left or right CIRCULAR polarization.
  2. jcsd
  3. Nov 14, 2016 #2


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    Staff: Mentor

    I don't know what an air molecule is, so I will assume you are considering nitrogen and oxygen. Visible light is not absorbed by air, so the answer is definitely no. Ro-vibrational transitions in N2 and O2 are also forbidden, so even IR will not get significantly absorbed. Since they have no permanent dipole moment, air is also pretty much transparent to microwave radiation also. You would need to induce electronic transitions (in the UV) to get those molecules to rotate.
  4. Nov 15, 2016 #3
    Thanks for the explanation Dr.Claude....
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