STRONG ATOM-CAVITY COUPLING OVER LARGE VOLUMES AND THE OBSERVATION OF SUBNATURAL INTRACAVITY ATOMIC LINEWIDTHS

Standard classical optical design procedures along with the intuitive concept of hour-glass-type optical modes are employed to produce cavities that provide strong atom-cavity coupling for atoms spread over a relatively large spatial region. Such cavities may be employed to provide macroscopic environments in which ordinarily microscopic quantum optical phenomena play an essential role. Concepts are tested through explicit cavity fabrication combined with an experimental study of cavity-mediated perturbations to the frequency and width of a spontaneous emission line in atomic barium. Manifestly subnatural emission linewidths are observed.