关键词: 电磁感应透明/
调制光谱/
Rydberg原子
English Abstract
Electromagnetically induced transparency of Rydberg atoms in modulated laser fields
Yang Zhi-Wei,Jiao Yue-Chun,
Han Xiao-Xuan,
Zhao Jian-Ming,
Jia Suo-Tang
1.State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China
Fund Project:Project supported by the National High Technology Research and Development Program of China (Grant No. 2012CB921603), the National Natural Science Foundation of China (Grant Nos. 11274209, 61475090, 61378013, 61378039), and the Shanxi Provincial Foundation for Studying Abroad, China (Grant No. 2014-009).Received Date:14 January 2016
Accepted Date:23 February 2016
Published Online:05 May 2016
Abstract:Rydberg atoms, with large principal quantum number n, have been widely investigated in recent years due to their peculiar properties, such as big sizes, long lifetimes and strong interactions with fields and other Rydberg atoms. Rydberg atoms are very sensitive to external fields due to their large polarizabilities scaling as n7.These make Rydberg atoms an ideal candidate for the quantum information, the many-body interaction, etc.In this work, we investigate the Rydberg atoms using electromagneticlly induced transparency (EIT) in a ladder three-level system. The EIT is a quantum interference effect between two excitation path-ways driven by two laser fields. The main idea is performed in a room temperature cesium vapor cell, where the probe laser frequency is modulated. The ground state (6P1/2), excited state (6P3/2), and Rydberg state (nS1/2) constitute a Rydberg three-level system, in which the probe laser is fixed to the 6S1/2 (F = 4)6P3/2 (F = 5) transition by saturated absorption spectrum technique, whereas the coupling laser is scanned across the 6P3/249S1/2 transition. We detect the demodulated EIT signal with the lock-in amplifier (SR830). The modulated EIT signal shows a two-peak structure. The measured spacing between two peaks increases with the frequency detuning, caused by the modulation amplitude, and half the spacing between the peak-to-peak is nearly 1.67 times the modulation amplitude of the probe laser; the measured result shows that the splitting is independent of the modulation frequency. The experimental results are in agreement with the theoretical calculations. The results in our work can be used for real-time monitoring of the laser-line profiles and the fluctuation of laser frequency.
Keywords: electromagneticlly induced transparency/
modulation spectrum/
Rydberg atoms
