  We present a theoretical investigation of optical cavity QED systems, as
described by the driven, open Jaynes-Cummings model and some of its variants,
as potential sources of steady-state Wigner-negative light. We consider
temporal modes in the continuous output field from the cavity and demonstrate
pronounced negativity in their Wigner distributions for experimentally-relevant
parameter regimes. We consider models of both single and collective atomic spin
systems, and find a rich structure of Wigner-distribution negativity as the
spin size is varied. We also demonstrate an effective realization of all of the
models considered using just a single 87Rb atom and based upon combinations of
laser- and laser-plus-cavity-driven Raman transitions between magnetic
sublevels in a single ground hyperfine state.
