Controllable phase-dependent optical switch in an atom-cavity system

Abstract Coherent perfect absorption (CPA) and coherent perfect transmission (CPT) are two extreme states arising from the manipulation of optical fields. Generally, CPA and CPT occur under different input-field phases. Therefore, we propose a scheme to realize an all-optical switch based on phase-dependent CPA–CPT conversion. In our proposal, the CPT state and the CPA state are treated as the on state and the off state, respectively. Consequently, the efficiency of this all-optical switch can reach the maximum value of 1. With the introduction of an incoherent pump field, the CPA state can be achieved under a weaker input probe field or can be converted into a CPT state. The results show that the optical switch can operate with weaker fields and can be further optimized by the application of an incoherent field.