Biexcitonic effects in the nonperturbative regime of semiconductor microcavities

Polarization-dependent transient pump-probe spectroscopy reveals important effects of biexcitonic interactions on coupled optical excitations in semiconductor microcavities. We show that exciton-to-biexciton transitions can result in a significant increase in normal mode splitting of cavity-polaritons, in sharp contrast to effects of nonlinear optical interactions such as band filling that reduce the splitting. A phenomenological model based on Maxwell-Bloch equations is developed to elucidate how biexcitonic effects contribute to cavity-polaritons. copyright 1998 The American Physical Society