when a wavefield is incident of an atom and the photon have the right energy (equal to the band gap energy), the photon is absorbed and disappear.....
But isn't the photon re-emitted later on and allowed to propagate through the material or does all its energy get lost into heat?
If the photon frequency omega is not equal to the resonance frequency, will the photon still excited the atoms in the material but the photon will be able to move through the material it as if the material was transparent? So each atom would absorb the photon and re-radiate it elastically if omega is not a resonant frequency?
If omega was a resonant frequency the atoms should still absorb, and re-emit the photon via spontaneous emission...I tend to associate spontaneous emission no with the disappearance of the photon but with a re-emission of it....