Active optical clock based on four-level quantum system  

作　　者：ZHANG TongGang WANG YanFei ZANG XiaoRun ZHUANG Wei CHEN JingBiao 

机构地区：[1]State Key Laboratory of Advanced Optical Communication Systems and Networks,Institute of Quantum Electronics,School of Electronics Engineering & Computer Science,Peking University

出　　处：《Chinese Science Bulletin》2013年第18期2033-2038,共6页

基　　金：supported by the National Natural Science Foundation of China (10874009 and 11074011)

摘　　要：Active optical clock,a new conception of atomic clock,has been proposed recently.In this work,we propose a scheme of active optical clock based on four-level quantum system.The final accuracy and stability of two-level quantum system are limited by second-order Doppler shift of thermal atomic beam.To three-level quantum system,they are mainly limited by light shift of pumping laser field.These limitations can be avoided effectively by applying the scheme proposed here.Rubidium atom four-level quantum system,as a typical example,is discussed.The population inversion between 6S 1/2 and 5P 3/2 states can be built up at a time scale of 10-6 s.With the mechanism of active optical clock,in which the cavity mode linewidth is much wider than that of the laser gain profile,it can output a laser with quantum-limited linewidth narrower than 1 Hz in theory.An experimental configuration is designed to realize this active optical clock.Active optical clock, a new conception of atomic clock, has been proposed recently. In this work, we propose a scheme of active optical clock based on four-level quantum system. The final accuracy and stability of two-level quantum system are limited by second-order Doppler shift of thermal atomic beam. To three-level quantum system, they are mainly limited by light shift of pumping laser field. These limitations can be avoided effectively by applying the scheme proposed here. Rubidium atom four-level quantum system, as a typical example, is discussed. The population inversion between 6S 1/2 and 5P3/2 states can be built up at a time scale of 10-6 s. With the mechanism of active optical clock, in which the cavity mode linewidth is much wider than that of the laser gain profile, it can output a laser with quantum-limited linewidth narrower than 1 Hz in theory. An experimental configuration is designed to realize this active optical clock.

关 键 词：主动光学 量子系统 四能级 时钟 三能级系统 激光增益 多普勒频移 粒子数反转 

分 类 号：O413.2[理学—理论物理] O562[理学—物理]