Active control of transmission and group velocity in one-dimensional photonic crystals

Phase-dependent and switchable transmission and group velocity are achieved for a light beam traveling through a one-dimensional photonic crystal containing a dispersive layer. By proper selection of phase difference between probe and coupling fields, the quantum interference in dopant atoms to the defect layer leads to controlling of delay time of transmitted and reflected light. This way, simultaneous subluminal transmission and reflection are achievable. We also found that transmission of one-dimensional photonic crystals is actively controllable in a wide range only by controlling the characteristics of incident light with no need for altering the effective indices or thicknesses of layers.