Rydberg Electromagnetically-Induced-Transparency Spectra in a Laser-Cooled Ensemble
Ko-Tang Chen1*, Bongjune Kim1, Yi-Hsin Chen1, Ite A. Yu1
1Department of Physics and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
* Presenter:Ko-Tang Chen
We present a systematical study of Rydberg-state electromagnetically-induced-transparency (EIT) spectra with various quantum number and laser power in a cold atomic system. One 780 nm probe field and one 480 nm coupling field form a cascade-type transition scheme, involving a highly-excited Rydberg state of nD5/2 where n = 30~57. The coupling Rabi frequency, optical density of the system, and decoherence rate can be individually determined by the spectra based on a theoretical model. Compared with the Λ-type EIT, the decoherence rate in Rydberg-EIT system is larger by 2 or 3 orders of magnitude, due to the fluctuation of sum of the frequencies of two independent lasers. We plan to reduce the decoherence rate via the Pound–Drever–Hall frequency-lock technique, and improve the storage efficiency of Rydberg polaritons.

Keywords: Rydberg atoms, Rydberg-EIT, Laser-cooled atoms