Asymmetric angular emission in semiconductor microcavities

Strongly angular-dependent emission properties are observed from a semicond uctor microcavity pumped along a critical angle of incidence. In contrast t o the luminescence from conventional semiconductor heterostructures, the em ission is completely asymmetrical with respect to the sample normal. The re sults imply that parametric scattering dominates the energy relaxation of p olaritons, and is enhanced by the deformed shape of the dispersion relation s.