Electromagnetically induced transparency and controllable group velocity in a five-level atomic system

Boris G. Matisov, A. Pushel, Laurentius Windholz

Lihui Jin, Shangqing Gong, Yueping Niu +1 more

The optical properties of a five-level atomic system composed of a 'Lambda'-type four-level atomic and a tripod four-level atomic systems are investigated. It is found that the behaviors of electromagnetically induced transparency (EIT) and group velocity can be controlled by choosing appropriate parameters with the interacting dark resonances. In particular, when all the fields are on resonance, the slow light at the symmetric transparency windows with a much broader EIT width is obtained by tuning the intensity of the coupling field in comparison with its sub-system, which provides potential applications in quantum storage and retrieval of light.

V. Priyadarshini, Nandhana Chishor, Phalgun Tomar +2 more

Luming Li, Hong Mei Guo, Feng Xiao +2 more

An M-type five-level atomic model is proposed to achieve a large index of refraction with vanishing absorption. We present a novel model, to our knowledge, in theoretical analysis, in which an incoherent pumping rate is adopted to simplify the M-type five-level system to be an equivalent four-level system. The theoretical and experimental results show that, by adjustment of the intensity of the incoherent pump, lower group velocity (than that obtained in a conventional Lambda-type three-level electromagnetically induced transparency system) is obtained in cesium atomic vapor. Moreover, a saturation limit for the group velocity is also presented. The experimental results show good agreement with the theoretical analysis.

Bor-Wen Shiau, Meng-Chang Wu, Chi-Ching Lin +1 more

We report on the first experimental demonstration of low-light-level cross-phase modulation (XPM) with double slow light pulses based on the double electromagnetically induced transparency (EIT) in cold cesium atoms. The double EIT is implemented with two control fields and two weak fields that drive populations prepared in the two doubly spin-polarized states. Group velocity matching can be obtained by tuning the intensity of either of the control fields. The XPM is based on the asymmetric M-type five-level system formed by the two sets of EIT. Enhancement in the XPM by group velocity matching is observed. Our work advances studies of low-light-level nonlinear optics based on double slow light pulses.

Jiahua Li, Wenyi Wang