Precise measurement of the line width of the photoassociation spectra of ultracold molecules by using a frequency shifter  

作　　者：武寄洲 马杰 姬中华 张一驰 李玉清 汪丽蓉 赵延霆 肖连团 贾锁堂 

机构地区：[1]State Key Laboratory of Quantum Optics and Quantum Optics Devices,Laser Spectroscopy Laboratory,College of Physics and Electronic Engineering,Shanxi University

出　　处：《Chinese Physics B》2012年第9期224-228,共5页中国物理B（英文版）

基　　金：Project supported by the National Basic Research Program of China (Grant No. 2012CB921603);the National High Technology Research and Development of China (Grant No. 2009AA01Z319);the National Natural Science Foundation of China (Grant Nos.61008012,10934004,60978018,60978001,60808009, and 11074154);the Science Fund for Creative Research Groups of the National Natural Science Foundation of China (Grant No. 60821004);the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20101401120004);the National Natural Science Foundation of Shanxi Province,China (Grant No. 2009011059-2)

摘　　要：We propose a technique to precisely measure the line width of the photoassociation spectra of the excited cesium molecule by using a frequency shifter to generate two laser beams with a precise frequency difference. A series of photoassociation （PA） spectra are recorded with two laser beam induced molecular lines, whose peak separation serves as an accurate frequency ruler to measure the line width of the PA spectra. The full width half maximum line width was studied as a function of PA laser intensity. The extrapolated value at zero laser intensity is （34.8± 0.22） MHz. By analyzing other broadening mechanisms, a value of （32.02 ± 0.70） MHz was deduced. It is shown that this scheme is inexpensive, simple, robust, and is promising for applications in a variety of other atomic species.We propose a technique to precisely measure the line width of the photoassociation spectra of the excited cesium molecule by using a frequency shifter to generate two laser beams with a precise frequency difference. A series of photoassociation （PA） spectra are recorded with two laser beam induced molecular lines, whose peak separation serves as an accurate frequency ruler to measure the line width of the PA spectra. The full width half maximum line width was studied as a function of PA laser intensity. The extrapolated value at zero laser intensity is （34.8± 0.22） MHz. By analyzing other broadening mechanisms, a value of （32.02 ± 0.70） MHz was deduced. It is shown that this scheme is inexpensive, simple, robust, and is promising for applications in a variety of other atomic species.

关 键 词：laser cooling molecular spectroscopy line shapes and width 

分 类 号：O562[理学—原子与分子物理]