Collision broadening in II-VI semiconductor microcavities -: art. no. 165340

We present a comprehensive study of the collision broadening in II-VI semiconductor microcavities. The polariton nonlinear coherent dynamics was investigated using angle-resolved four-wave mixing, which allows us to study the polariton dephasing on a large scale within reciprocal space. The low-energy polariton dephasing time is found to present a threshold dependence with excitation angle as well as excitation density, associated with the possibility, for polaritons with large enough in-plane wave vectors to scatter towards the high density of states excitonic reservoir. The validity of the polariton-polariton scattering calculation based on the effective exciton-exciton interaction hamiltonian is also discussed.