Electromagnetically induced transparency using very weak coupling fields

Liu Zheng-Dong, Wu Qiang, (1)南昌大学（北区）近代物理研究所，南昌 330047; (2)浙江工业大学应用物理系，杭州 310032

We study the spontaneous emission in a fourlevel atomic system driven by three coupled fields. We have demonstrated the existence of electromagnetically induced transparency (EIT) with a set of suitable parameters, and we find that the light levels of the drive fields are as weak as that of the spontaneous emission with the EIT.

A. Kasapi, G. Y. Yin, Manoj Kumar Jain +2 more

Xiaoli Li, Lianshui Zhang, Lijun Yang +2 more

Lijun Yang, Dong-qi Lu, Min Zhao

We present a theoretical study on the spectral linewidth of electromagnetically induced transparency (EIT) in a cyclic three-level atomic system coupled by double coupling fields and a microwave field. The absorption profiles are obtained by a weak probe field scanning corresponding transition. It is shown that for definite Rabi frequencies of interacting fields the spectral linewidth of transparency windows depends on the relative phase between two coupling fields. In particular, as the relative phase of the double coupling fields approaches to , the linewidth narrows distinctly. This proposes a way to controlling spectral width of EIT by changing the relative phase between two fields.

Min Kyeong Kim, Lim Lee, Xumei Su +1 more

We have measured electromagnetically induced transparency (EIT) and four wave mixing (FWM) signals in a three level atomic system to enhance nonlinearity for a weak field due to quantum coherence with standing fields. We were able to observe quite different EIT signals according to a traveling or standing coupling field. (1) We obtained EIT and FWM signals depending on detunings, polarization, (2) and power of the coupling field. Our results will be analyzed theoretically in viewpoint of a photonic band gap model.

Mikhail D. Lukin, Ataç İmamoğlu