Propagation of the probe field through a chiral medium with four-level atoms

Abstract

We examine propagation of the linear polarized pulse through a medium containing four-level double V-type atoms. The medium is made chiral by the cross coupling of the applied electromagnetic fields. We show that such medium can be used as a polarization splitter of the probe pulse where the spatially refracted left and right circular polarized components propagate independently due to their distinct phase velocities. We find that dispersion characteristics of the chiral medium can be manipulated by the controlling parameters of the system. Consequently, both the left and right circular polarized components exhibit sub and superluminal propagation characteristics for suitable choices of the probe field detuning and external control fields. It is found that for both polarized components a switching from sub to superluminal behavior may be achieved by adjusting the probe field detuning. In addition, splitting of the left and right circular polarized components and hence peak value of the group time delay and advance may be tuned via the strengths of the control fields. Our results may find applications in spintronics, magnetic quantum optics, images coding and cloaking technology.