Journal of Physics B Atomic Molecular and Optical Physics
Widening and shifting of the EIT windows in a multi-driven transitionFe= 1 Fg= 2
Ying Gu, Qingqing Sun, Qihuang Gong
Abstract
For a closed transition Fe = 1 ↔ Fg = 2 driven by linearly polarized light and probed by circularly polarized light, quantum coherence effects induced by the Zeeman sublevels belonging to the different states are investigated. When the Zeeman splitting Δe of the excited level is larger than the Zeeman splitting Δg of the ground level, by increasing the drive Raby frequency, only the widening of the electromagnetically induced transparency (EIT) window with positive dispersion is found. In the opposite case, i.e. Δe ≤ Δg, in a moderate drive Rabi frequency, electromagnetically induced absorption with negative dispersion is obtained due to the shifting of the transparency points. Moreover, for the case of Δe ≤ Δg, a transition from subluminal to superluminal light propagation is predicted at the zero pump–probe detuning.