Why don't electrons go into the next orbit during stimulated emission? Hey all, I was studying stimulated emission in lasers and I had a doubt regarding the same. When the electron collides with another which is in an excited state, why doesn't the electron, which gets collided, move into the next orbit? Why does it radiate a photon and goes into the ground state? It would be great if someone could explain it to me in simple terms. Thank you.