Dephasing of strongly coupled exciton-photon systems

The coherent dynamics of cavity-polaritons are investigated using the four-wave-mixing technique. A series of experiments on four samples operating in both the weak and strong coupling regimes were performed to study the influence of strong coupling on the interaction of cavity-polaritons with other cavity-polaritons, free carriers and acoustic phonons. Due to Rabi splitting a larger number of free carriers are created in the strong coupling sample compared with the weak coupling sample. This has a significant impact on the total scattering efficiency. The temperature dependence of the four-wave mixing yields evidence of suppression of acoustic phonon scattering compared to bare quantum well behaviour and is a result of the modified two dimensional dispersion.