What effect does laser irradiation have on an electron?

Question

egenriether · Answer

If the electron is in an atom the effect would be to raise the electron to a higher orbital, or knock it off its atom (photoelectric effect) if the atom was part of a solid.  If in a gaseous state the energy of the photon would have to correspond to the jump in energy to another level by E =hf, to raise the electron's energy level.  In the solid some of the excess energy is dissipated as phonons (or equivalently the energy bands are spread into a continuous spectrum, which is why heating up a solid makes it turn many colors up to white, but a gas has a discrete spectrum).  A lone (ionized) electron by itself would be knocked away by a photon and the photon scattered (i.e. Compton scattering in the case of gamma or x-rays).  Sorry for the long answer but it all depends on what state the electron is in.  The actual answer is much more complex than I've said here.  For a complete description on the interaction of light and matter, look up quantum electrodynamics on the web.

anonymous · Answer

Thanks. The thing I was reading about was actually when a laser was focused on nuclei which had just been photoelectriced, the electron fell back into an orbital. Is there an explanation for this or did I misread it?

egenriether · Answer

I'm not exactly sure what you mean.  The laser is pointed at a nucleus that has had its electrons ionized (knocked off) and that caused the electrons to come back to the atom?  If so I don't know about that, otherwise correct my thinking and I will try to help further.