Phase conjugate degenerate four-wave mixing in molecular aggregates

Abstract

Abstract We investigate phase conjugate degenerate four-wave mixing (DFWM) in molecular aggregates consisting of N interacting, homogeneously broadened two-level systems in a cyclic configuration with a dimension much smaller than an optical wavelength. The interaction includes both the static dipole-dipole coupling and superradiant coupling. We show that, in general the size dependence of χ(3) is determined by the relative magnitudes of the homogeneous dephasing rate and the superradiant decay rate. We predict the existence of a narrow dephasing-induced resonance superposed on the broader superradiant exciton lineshape.