Polariton parametric amplifier: pump dynamics in the coherent regime

J. Tignon , Agnès Huynh (1) , Ph. Roussignol , C. Delalande , R. André , R. Romestain , Si Dang D. Le

1 LMDH - Laboratoire des Milieux Désordonnés et Hétérogènes

We present a comprehensive study of the polariton coherent dynamics in II-VI semiconductor microcavities. An angle resolved four-wave mixing experiment has been developed, which allows us to study the polariton dephasing within the full reciprocal space. We observe two main trends: (i) pump polaritons that are excited above the threshold and in the phase matching condition for parametric amplification threshold are observed to scatter much more efficiently towards the final states (signal and idler), inducing pump depletion, and (ii) below this threshold or when the phase matching condition is not fulfilled, we observe an angle-dependent collision broadening, that occurs when pump polaritons can scatter towards the excitonic reservoir. Both dynamics are then analysed using a numerical model that reveals a complex interplay and competition between collision broadening and parametric amplification. In particular, it is shown how collision broadening must be taken into account in order to explain the gain saturation observed in the parametric amplification process.

J. Tignon, Agnès Huynh, Ph. Roussignol, C. Delalande, R. André, et al.. Polariton parametric amplifier: pump dynamics in the coherent regime. physica status solidi (a), 2004, France. pp.633, ⟨10.1002/pssa.200304062⟩. ⟨hal-00004954⟩