Phase control of coherent pulse propagation and switching based on electromagnetically induced transparency in a four-level atomic system

Abstract

We investigate the propagation and control of a weak probe laser pulse in a tripod-type four-level atomic system with a quantum loop scheme. The propagation of the probe pulse depends sensitively on the relative phase of the driving fields. By numerically solving the coupled Maxwell–Bloch equations, it is shown that the dynamic control and switching operation of the probe pulse are possible via changing the relative phase of the driving fields. This work may provide a useful reference for designing optical switching and optical storage devices.