Abstract

Importance of the effects associated with the four-particle correlation in the nonlinear optical response at the fundamental band edge has been revealed in a number of four-wave mixing (FWM) experiments in χ⁽³⁾-regime. In the spectral window close to the exciton resonance the effects of four-particle correlation can be classified in terms of spin-dependent interaction between excitons. However, the role of the memory effects, which are responsible for the temporal evolution of the 2ω-coherence within continuum of unbound two-exciton states and for a long-living coherence due to the existence of biexciton, remains unclear. The studying in the effects of the bound and unbound two-exciton states is especially interesting in GaAs system where the biexciton binding energy is of the order of the exciton linewidth. Here we report on the study of the memory effects by polarization-sensitive DFWM in high-Q microcavity. We estimate the correlation time of exciton interaction in GaAs and obtain the relative contributions from the bound and unbound two-exciton states to the DFWM signal.

© 2000 IEEE