Nonclassical photon correlations from two-level atoms in an optical cavity

A theoretical and experimental study of the nonclassical photon statistics produced when two-level atoms are strongly coupled to a single mode of the electromagnetic field inside an optical resonator has been carried out. The system is a simple one to understand conceptually and such a model has been used for many years as a paradigm in quantum optics. Three different approaches are presented for calculating the main quantity of interest here, the second order intensity correlation function; the results will be compared and the limitations of each method will be discussed. Of central importance is the experiment which was designed and built with the goal of observing these nonclassical properties. The experimental apparatus will be described in detail and results demonstrating the nonclassical nature of the observed photon correlations will be presented. A discussion of the nonclassical effects in terms of an interference of quantum probability amplitudes and the collapse of the wavefunction of the coupled system will be presented.