Polarization-anisotropy induced spatial anisotropy of polariton amplification in planar semiconductor microcavities

Based on a microscopic many-particle theory we investigate the amplification of polaritons in planar semiconductor microcavities. We study a spatially perfectly isotropic microcavity system and excitation geometry. For this system, our analysis shows that a pump-induced vectorial polarization anisotropy can lead to a spatial anisotropy in the stimulated amplification of polaritons. This effect is brought about by the interplay of the longitudinal-transverse cavity mode splitting (TE-TM splitting) and the spin-dependence of the polariton-polariton scattering processes.