Parametric oscillation in a vertical microcavity: A polariton condensate or micro-optical parametric oscillation

Semiconductor microcavities can support quasiparticles which are half-light and half-matter with interactions possessed by neither component alone. We show that their distorted dispersion relation forms the basis of a quasipa rticle "trap" and elicits extreme enhancements of their nonlinear optical p roperties. When driven by a continuous wave laser at a critical angle, the quasiparticles are sucked into the trap, condensing into a macroscopic quan tum state which efficiently emits light. This device is thus an optical par ametric oscillator based on quasiparticle engineering. In contrast to a las er, macroscopic coherence is established in the electronic excitations as w ell as the light field. This paves the way to new techniques analogous to t hose established in atomic and superconducting condensates, such as ultrase nsitive solid-state interferometers.