Surely the whole point of laser cooling is that the atom does not return to its original ........
in order for the atom to slow down further and further ( or cool down more and more ) energy must be lost from the atom itself repeatedly and the only way possible for that to occur is if the atom emits a photon of a higher energy than the photon that impacted the atom initially.
because a normal change from an excited state to a stabilized state places the energy of the atom back to its initial energy , its frequency returns to its initial frequency and its electrons orbits return to there initial orbits.
and with this experiment we see that energy is lost
because we see the atom slowing down
and the only element involved that could possibly account
for the lost energy would be the emission of a higher charged photon.
so that is where the energy goes !
Where would this extra-energetic photon go. Saying it is emitted by an individual atom does not account for its loss in terms of the system.
in the experiment it is not the system that caused the cooling
that is the focus , and as far as I can tell the photon is immediately out of focus as soon as it is emitted.
in the experiment the focus is on the slowing or cooling of the atom itself and everything outside its physical boundaries are of no concern.
