Optical controlling the spectral singularity in a doped slab

Abstract

In this work, we have used the probe and control fields to theoretically investigate optical spectral singularity (OSS) in a doped and gained (DG) slab. This slab is composed of a gain medium modeled by two-level atoms and doped by the three-level $\Lambda$ -type atoms. This work is based on calculations and the results show that the OSS effect can be switched on and off by changing the relative phase of the fields from 0 to $\pi$ . Also, in comparison with an undoped slab, the OSS effect appears for lower values of gain. For a given value of gain coefficient at $\phi = 0$ , the DG slab produces a sharp OSS with infinite transmission but, for $\phi = \pi$ , the slab acts as an optical filter with a narrow bandwidth around the wavelength of OSS. We have also illustrated that it is possible to tune the wavelength of OSS just by tuning the relative phase.