Experimental Evidence of Bosonic Statistics and Dynamic Bec of Exciton Polaritons in GaAs and CdTe Quantum Well Microcavities

We present experimental evidence for the final state stimulation for the exciton-exciton scattering rate into the upper and lower exciton-polaritons in a GaAs quantum well microcavity. We have studied the reservoir exciton density, lower polariton population, and time delay dependence of the stimulated scattering rate, and have found the behavior to be in agreement with a theoretical prediction. We then describe a dynamic BEC of exciton-polaritons in a CdTe quantum well microcavity. By performing a pulsed pump and probe experiment, we observe unambiguous evidence of real excited exciton-exciton scattering gain in the form of exp(const \cdot N_exc²), where N_exc is the exciton reservoir population.