Ultrafast all-optical polarization switching based on “virtual excitation” of InGaAs(P) MQWs

All-optical polarization switches based on near-resonant excitation have been demonstrated recently, which operate without significant real carriers excited in MQWs so as to avoid carriers accumulation. In this paper, we focus our investigation on the switch adopting InGaAsP MQWs because it could be compatible with the optical communication system. Our theoretical analysis is restricted to χ3 regime (i.e., the lowest-order nonlinear regime) and based on the dynamics-controlled truncation (DCT) scheme which provides a formalism for studying the coherent dynamics in weakly-nonlinear coherent optics of semiconductors. By using the theoretical model based on DCT theory, the switching action was simulated. With this theoretical model, we study the respective contributions of phase space filling and Hartree-Fock mean field as main terms of the optical Stark effect to the switching process, then exhibit the influence of delay time and control intensity for the switching response.