Realization of population inversion between 7S_(1/2) and 6P_(3/2) levels of cesium for four-level active optical clock  

作　　者：WANG YanFei WANG DongYing ZHANG TongGang HONG YeLong ZHANG ShengNan TAO ZhiMing XIE XiaoPeng 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：《Science China(Physics,Mechanics & Astronomy)》2013年第6期1107-1110,共4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. 10874009 and 11074011)

摘　　要：We demonstrate experimentally the population inversion between 7S1/2 and 6P3/2 levels of cesium in thermal cesium cell with a 455.5 nm pumping laser.We calculate the relative population probabilities at each level theoretically with the density matrix method.In a steady state,5.8% atoms are at 7S1/2 level and 2.9% at 6P3/2 level,which builds up the population inversion between the two levels.We obtain the fluorescence spectra produced in thermal cesium cell in our experiment.The measured relative intensity of each available fluorescence spectral line in the experiment agrees very well with the theoretical result.The demonstrated population inversion between 7S1/2 and 6P3/2 levels can be used to construct an active optical clock of four-level system with a wavelength of 1469.9 nm.We demonstrate experimentally the population inversion between 7S1/2 and 6P3/2 levels of cesium in thermal cesium cell with a 455.5 nm pumping laser.We calculate the relative population probabilities at each level theoretically with the density matrix method.In a steady state,5.8% atoms are at 7S1/2 level and 2.9% at 6P3/2 level,which builds up the population inversion between the two levels.We obtain the fluorescence spectra produced in thermal cesium cell in our experiment.The measured relative intensity of each available fluorescence spectral line in the experiment agrees very well with the theoretical result.The demonstrated population inversion between 7S1/2 and 6P3/2 levels can be used to construct an active optical clock of four-level system with a wavelength of 1469.9 nm.

关 键 词：active optical clock four-level system population inversion 

分 类 号：O572.2[理学—粒子物理与原子核物理]