Suppressed polariton scattering in semiconductor microcavities

Ultrafast time-resolved measurements on a semiconductor microcavity distinguish polariton dynamics dependent on the detuning between the constituent photon and exciton modes. Spectral synthesis allows the injection of specific polariton pulses into the sample. Scattering which results in absorption is found to be suppressed in the lower polariton branch by the combined action of normal mode splitting and motional narrowing. The experimental difference between angle and position tuning demonstrates the role of the polariton dispersion in polariton-polariton interactions