Abstract

Many field states in quantum optics may be regarded as quasiclassical in that they possess a fairly well-defined phase and amplitude in the limit in which the average number of photons is large. Examples include coherent states and squeezed states that have a coherent component substantially larger than the squeezed noise contribution. For such states, calculations involving sums over the coefficients in the Fock-state basis can be considerably simplified in the limit of large photon number. The Jaynes-Cummings model and its extensions (to, e.g., three-level, two-mode configurations) may be advantageously studied from this perspective. New results on the three-level, two-mode problems, on the influence of cavity losses, and on the various time scales of interest will be presented here. The method typically identifies a set of privileged, long-lived atomic states, which lead to a quasiclassical evolution that agrees with the prediction of semiclassical treatments over a characteristic time scale; linear combinations of the long-lived states, on the other hand, become superpositions of macroscopically distinct states in time and result in an evolution that exhibits many uniquely quantum effects.

© 1992 Optical Society of America