Light-polarization and intensity dependence of higher-order nonlinearities in excitonic FWM signals

A theory-experiment comparison for the intensity and polarization dependence of spectrally resolved transient four-wave-mixing signals is presented for a ZnSe single quantum well. Results for high intensities deviate from a simple model based on the optical Bloch equations for a five-level system whereas a microscopic theory for coherent excitonic and biexcitonic nonlinearities shows excellent agreement. Copyright Springer-Verlag Berlin/Heidelberg 2004