COHERENT DYNAMICS OF EXCITONIC NONLINEAR-OPTICAL RESPONSE IN THE NONPERTURBATIVE REGIME

We report experimental and theoretical studies of the transient nonlin ear response from semiconductor microcavities. We show that, in the no nperturbative regime, oscillations in time-integrated transient four-w ave mixing do not correspond to normal mode oscillations of either the exciton or photon population in the cavity. Coherent nonlinear respon ses arising from band filling, excitation-induced dephasing, and renor malized electric fields feature highly distinctive dynamical behaviors . Coherent dynamics in transient four-wave mixing reflects interferenc e between these nonlinear processes. dynamics in transient four-wave m ixing reflects [S0031-9007(98)07305-0].