The manipulation of light pulse from subluminal to superluminal propagation in a degenerate two-level Cs atomic system  

作　　者：ZHANG Jun Xiang JIANG Qi Chang LIU Chao ZHANG Xin Sheng LIU Jin Hong 

机构地区：[1]The State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University

出　　处：《Science China(Physics,Mechanics & Astronomy)》2014年第12期2246-2250,共5页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11274210 and 61308121);the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20131401110013);the Undergraduate Student Innovative Experiment Program

摘　　要：We experimentally demonstrate the propagation of light pulse from subluminal to superluminal light based on quantum coher- ence in a degenerate two-level atomic system in a Cs vapor cell. It is shown that the group velocity of light pulse can be switched from subluminal to superluminal propagation via changing the coupling field from a traveling wave to a standing wave, while can also be continuously manipulated by varying the intensity of two waves superposed to form a standing wave. The observed maximum delay and advance times are about 0.45 and 0.54 μs, corresponding to the group velocity of v8 = 168 km/s and ve =-138 krrt/s, respectively. This investigation may have the practical applications of devices for optical tunable delay lines, optical switching and optical buffering.We experimentally demonstrate the propagation of light pulse from subluminal to superluminal light based on quantum coherence in a degenerate two-level atomic system in a Cs vapor cell.It is shown that the group velocity of light pulse can be switched from subluminal to superluminal propagation via changing the coupling field from a traveling wave to a standing wave,while can also be continuously manipulated by varying the intensity of two waves superposed to form a standing wave.The observed maximum delay and advance times are about 0.45 and 0.54μs,corresponding to the group velocity of g=168km/s and g=138 km/s,respectively.This investigation may have the practical applications of devices for optical tunable delay lines,optical switching and optical buffering.

关 键 词：group velocity SUBLUMINAL SUPERLUMINAL quantum coherence standing wave 

分 类 号：O413[理学—理论物理]