One-dimensional atoms

Abstract

By strongly coupling a single atom to a single mode of an optical cavity, we have achieved a system that approximates a 'one-dimensional' atom. Such a 1-D atom can be efficiently coupled to the essentially 1-D collimated fields of typical light beams. The dominance of coherent coupling (to the Gaussian mode of a Fabry-Perot cavity) over incoherent emission (into free space) is demonstrated by presenting results of both linear and nonlinear spectroscopic studies of the atom-cavity system. A novel feature revealed by these measurements is that saturation of the 1-D atom occurs for only 0.02 intracavity photons. Furthermore, the fraction β of atomic spontaneous emission emitted into the cavity mode is β ≈ 0.7.