Optical properties of an inhomogeneously broadened multilevel V-system in the weak and strong probe regimes

We present a theoretical model, using density matrix approach, to study the effect of weak as well as strong probe field on the optical properties of an inhomogeneously broadened multilevel V-system of the Rb-87 D2 line. We consider the case of stationary as well as moving atoms and perform thermal averaging at room temperature. The presence of multiple excited states results in asymmetric absorption and dispersion profiles. In the weak probe regime, we observe the partial transparency window due to the constructive interference that occurs between transition pathways at the line center. We present our results after carrying out Doppler averaging at room temperature atomic vapor and observe that the line width of transparency window is enhanced, whereas the positive slope of corresponding dispersion curve become less steep. In the presence of strong probe field, the transparency window (with normal dispersion) at line center switches to enhanced absorption (with anomalous dispersion). Here, we also present the dependence of electromagnetically induced transparency on the polarization of applied fields. In the end, we present transient behavior of our system which agrees with corresponding absorption and dispersion profiles. This study may help to understand optical switching and controllability of group velocity