What happens when two EM waves collide on matter?

toneboy1

I was wondering, if two EM waves of the same freq could add via superposition ON THE SAME ELECTRON or atom (at the same time) to become ionizing? For argument's sake say if each wave was just below UV

I remember E = hf, which would indicate no, I don't see how the energy would not add (thinking of mechanical waves).

THANKS!

Astronuc

See Rayleigh and Thomson scattering.

http://farside.ph.utexas.edu/teachin...es/node86.html
http://farside.ph.utexas.edu/teachin...es/node85.html

toneboy1

That is a fantastic resource, but I'll be honest, a lot of it I couldn't follow through completely.
In layman's terms. From what I could gather, they do both impart energy on a (for instance) electron but not equal to the sum of both?
So two high frequency waves could not add to become Ionising (??)

Thanks!

mfb

With high-intensity lasers, it is possible to do this - something like up to ~20 photons can be used to ionize a particle. Unfortunately, I do not remember the speaker of the talk where I heard about that, so I cannot give you a reference here. However, two-photon microscopy uses the same idea with 2 photons.

toneboy1

Interesting article. I had in mind two random EM waves coming together by chance but I suppose that would almost be impossibly unlikely. Moreover as to become ionising you would need like "20 photons".

By chance, do you happen to know if things like dipole moments are caused by the B part of an EM wave, or just the E half (portion) of the wave?

mfb

Two photons from different beams would be possible, too, just more difficult to achieve.

Induced electric dipole moments? Induced magnetic dipole moments? ;)

toneboy1

Quite so.