Role of different types of subsystems in a doubly driven Λ system in 87 Rb

TLDR: In this article, Chanu et al. presented a detailed theoretical study of the different possible subsystems created by the doubly driven ε-Lambda system and explored the possibility of tuning the strength of individual subsystems by changing the polarization of the control lasers.

Abstract: The well-known $\ensuremath{\Lambda}$ system using two ground-state hyperfine levels, ${F}_{g}=1$ and ${F}_{g}=2$ of $5{S}_{1/2}$, and one hyperfine level, ${F}_{e}=2$ of excited state of $5{P}_{3/2}$ of ${}^{87}$Rb, has been recently studied using two counterpropagating control lasers [Sapam Ranjita Chanu, Kanhaiya Pandey, and Vasant Natarajan, Europhys. Lett. 98, 44009 (2012)]. The experiment shows conversion of electromagnetically induced transparency into electromagnetically induced absorption because the doubly driven $\ensuremath{\Lambda}$ system forms various subsystems. We here present a detailed theoretical study of the different possible subsystems created by this configuration. We also explore the possibility of tuning the strength of individual subsystems by changing the polarization of the control lasers.