Abstract

The most basic problem of radiation-matter coupling is the interaction of a single two-level atom with a single-mode electromagnetic field. This problem received a great deal of attention shortly after the maser was invented.¹ At that time the problem was of purely academic interest, since in the experiments it was always necessary to have a large number of atoms and photons. This was due to the impossibility of detecting small amounts of atoms and the small size of the transition matrix elements resulting in atom–field coupling times much longer than other characteristic times of the system, such as atomic relaxation or the interaction time with the field.

© 1986 Optical Society of America