Nonlinear Optical Effects with Polariton Lasers in a GaAs Microcavity

We report the nonlinear optical properties of polaritons in a single quantum well GaAs microcavity. Single and double resonance cavities have been used to enhance the nonlinear effect of a nonlinear medium in high-Q quality factor cavities due to the cavity field amplification. On the other hand, such a cavity can generate polaritons, which condense (Bose-Einstein condensation) for determined conditions, such as cavity detuning and polariton density. Here, we present experimental observations of the second harmonic generation from polaritons in a GaAs microcavity, which exhibit a 2 order higher efficiency than those from the usual method. Furthermore, the efficiency is particularly high when the polariton is a photon-like particle and in a condensed state.