Phase control of all-optical switching based on spontaneously generated coherence in a three-level Λ-type atomic system

Controllable all-optical switching by relative phase and spontaneously generated coherence in a three-level Lambda-type atomic system is our aim in this study. We have generated a near-square probe pulse train with a similar modulation period through periodic modulation of the relative phase or coupling field intensity. Results show that the spontaneously generated coherence and phase range have a strong influence on the efficiency and shape of the switching pulse. Furthermore, the phase switching performance is enhanced as spontaneously generated coherence increases with incoherent pumping. In addition, synchronous or asynchronous switching of the probe pulse is observed in different phase domains (0-pi or pi-2 pi). The studied scheme may be helpful for use in the design of optical switching devices in optical communications.