Signal-power absorbtion by a collection of atoms: Where does the absorbed power go? Consider the net steady-state power per unit volume that is absorbed by the atoms, from the applied signal, in a simple two-level atomic system as a function of the applied signal strength W12=W21. Plot how this absorbed power varies with signal strength W12, and discuss the behavior especially at very small and very large W12. Where does the absorbed power go? -and how does it get there?