How do the stimulating photons actually bring the the already excited atoms to the ground state?
Stimulated emission is really a quantum mechanical phenomenon but it can be understood in terms of a “classical” field and a quantum mechanical atom. Electrons and how they interact with each other and electromagnetic fields form the basis for most of our understanding of chemistry and physics. Electrons have energy in proportion to how far they are on average from the nucleus of an atom. However, quantum mechanical effects force electrons to take on quantized positions in orbitals. Thus, electrons are found in specific energy levels of an atom When an electron is excited, it will not stay that way forever. On average there is a half-life for any particular energy level after which half of the electrons initially in that state will have decayed into a lower state. When such a decay occurs, the energy difference between the level the electron was at and the new level must be released either as a photon or a phonon. When an electron decays without external influence it is said to be due
