  Exciton-polariton condensates are considered as a deterministic source of
bright, coherent non-Gaussian light. Exciton-polariton condensates emit
coherent light via the photoluminescence through the microcavity mirrors due to
the spontaneous formation of coherence. Unlike conventional lasers which emit
coherent Gaussian light, polaritons possess a natural nonlinearity due to the
interaction of the excitonic component. This produces light with a negative
component to the Wigner function at steady-state operation when the phase is
stabilized via a suitable method such as injection locking. In contrast to many
other proposals for sources of non-Gaussian light, in our case, the light
typically has an average photon number exceeding one and emerges as a
continuous wave. Such a source may have uses in continuous-variable quantum
information and communication.
