Nonlinear polaritonic effects in photonic wires

A theoretical description of polaritons in quasi-one-dimensional microcavities is given where the nonlinear effects due to Coulomb exciton-exciton interaction and phase space filling are included explicitly. Analytical results are obtained for the power and time dependences of the optical response including anomalous amplification at short delay times and scattering between quasi-one-dimensional subbands from the lower as well as from the upper polariton branches. Spin quantum beats for the long delay times are shown to be consistent with exchange splitting of optically active excitons induced by uniaxial strain. The power and exchange splitting dependences of this response are obtained. The nonlinear approach describing the optical effects for both time scales are similar and include the exchange interaction for longer delay times.