Nonlinear reflectivity of strongly coupled exciton-photon systems under resonant and non-resonant pumping

Coupled exciton-photon systems are investigated using the pump-probe techni que in order to gain a better understanding of the important mechanisms gov erning cavity-polariton nonlinear behaviour and dynamics. A semiclassical m odel is used to describe the nonlinear behaviour and identify the dominant nonlinear mechanisms. Our phenomenological model produces very good agreeme nt with experiment. The influence of free carriers on nonlinearities in the strong coupling regime was studied directly using. non-resonant pump-probe . (C) 2000 Elsevier Science B.V. All rights reserved.