Polariton parametric amplifications in organic microcavities

Nonlinear processes involving polaritons in organic crystalline microcavities are theoretically studied by taking the kinematic polariton-polariton interactions as a source of nonlinearity. The polariton mean-field equations of motion are derived and used to explain the polariton parametric amplifications, which are predicted here for angle-resolved resonant pump-probe experiments in organic microcavities. We show that around zero exciton-photon detuning and for long-wavelength polaritons in a laterally confined microcavity, the polariton kinematic interactions result in a blueshift in the amplified probe field, while for large negative detuning the amplified probe field is redshifted. The parametric amplifications are studied for different processes which include the upper and lower polariton branches.