Negative Refractive Index in a Four-Level Atomic System
ZHANG Hong-Jun1,2,3, GONG Shang-Qing1, NIU Yue-Ping1, LI Ru Xin1, XU Zhi-Zhan1
1State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Shanghai 201800
2Graduate School of Chinese Academy of Sciences, Beijing 100049
3School of Physics and Information Technology, Shaanxi Normal University, Xi’an 710062
Negative Refractive Index in a Four-Level Atomic System
1State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Shanghai 201800
2Graduate School of Chinese Academy of Sciences, Beijing 100049
3School of Physics and Information Technology, Shaanxi Normal University, Xi’an 710062
Abstract： We propose a scheme for realizing negative refractive index in a four-level atomic system. It is shown that such a system can simultaneously exhibit negative permittivity and negative permeability in an optical frequency range. Furthermore, by analysing the dispersion property of the left-handed material, we find that the probe beam can be controlled from superluminal to subluminal or vice versa via choosing appropriate parameters.
2006, Vol. 23 
