Coherent-State Description of the Electromagnetic Field

Abstract

In this chapter we show that in the quantum theory of the electromagnetic field there exist quantum coherent states, in which the quantum correlation functions factorize in the form (3.53), i.e. a field in such a state satisfies the full coherence conditions. We discuss the basic properties of these states. Although the coherent states were first introduced by Schrödinger (1927) and were studied by others [e.g. Klauder (1960)], their full utilization in connection with quantum optics is due to Glauber (1963a-c, 1964, 1965, 1966a, b, 1969, 1970, 1972), who used them to study the quantum coherence of optical fields. Generalizations of this concept have been discussed in the Introduction.