Absorption, emission, and scattering of radiation
So far we have concentrated on the properties of electromagnetic fields. Now we study how electromagnetic fields interact with matter and how the outcome of the radiation–matter interaction can depend on the nonclassical properties of electromagnetic fields. Furthermore, in order to appreciate Glauber’s quantum theory of optical coherence [1, 2] in the next chapter we have to understand how a photo detector responds to incoming nonclassical light. In this chapter we treat the radiation–matter interaction perturbatively; the nonperturbative results will be given in later chapters.
7.1 The interaction of radiation and matter in the electric dipole approximation
We keep the analysis of ...