Giant enhanced four-wave mixing efficiency via two-photon resonance in asymmetric quantum wells

We propose an efficient four-wave mixing (FWM) scheme in asymmetric semiconductor quantum wells (SQWs) via two-photon resonance. By using the coupled Schrodinger-Maxwell formalism, we derive explicitly the corresponding analytical expressions of the inter-probe pulse and generated FWM field in the linear regime under the steady-state condition. With the aid of cross coupling between one ground state and two closely adjacent excited states, the efficiency of the generated FWM field is found to be significantly enhanced, up to 60%. More interestingly, a wide region of the maximum FWM efficiency is demonstrated as the ratio of transition dipole moments is within the values ranging from 1.1 to 1.3, which can be maintained for a certain propagation distance (i.e. 100 mu m).