一种实现冷原子束聚集的微磁透镜新方案  

A new mini-magnetic lens proposal for coverging the clod atoms

作　　者：许忻平[1] 张海潮[1] 王育竹[1] 

机构地区：[1]中国科学院上海光学精密机械研究所,量子光学重点实验室,中国科学院冷原子物理中心

出　　处：《物理学报》2012年第22期196-202,共7页Acta Physica Sinica

基　　金：国家重点基础研究发展计划(批准号:2006CB921202);国家自然科学基金(批准号:10974210)资助的课题~~

摘　　要：本文报道了对87Rb冷原子云聚焦的微磁透镜实验.磁透镜的核心部件是一个半径为2mm的微型线圈.当冷原子云沿线圈轴向运动到线圈附近时,线圈产生的非均匀磁场会对原子云实现纵向压缩.在线圈电流加载时间为10ms的情况下,原子云纵向尺寸随线圈电流增加先表现为会聚趋势;在某一电流值(0.9A)之后,表现为扩散趋势.与不加载线圈电流的情形相比较,电流为0.9A时的冷原子云纵向尺寸缩小了一个多量级,透镜焦距约为1.3mm.通过同时调节线圈电流的大小和作用时间,可实现对透镜焦距的调节.同时用数值模拟方法模拟了实验过程,模拟结果与实验结果基本符合.A mini-magnetic lens for laser-cooled rubidium atoms is experimentally demonstrated in this paper. The key component of the mini-magnetic lens is a mini-coil with a radius of 2 mm. When the cold atomic clouds are transported in the vicinity of the coil along its axial, they are compressed in the longitudinal direction due to the interaction with the non-uniform magnetic field of the coil. Given a current carrying time of about 10 ms, the atomic clouds tend to be gradually compressed in the axial direction with the increase of the coil current. When the coil current is greater than 0.9 A, the atomic clouds begin to expand. At a threshold value of 0.9 A, the focus length of the mini-magnetic lens is determined to be about 1.3 mm. Compared with the case that no current passes through the mini-coil, the dimension of the focused atom clouds is one order of magnitude smaller. Moreover, the focus length can be controlled by both the coil current and its carrying time. Numerical simulations are also given which are in agreement with the experimental results.

关 键 词：微磁透镜 磁场力 激光冷却 

分 类 号：O431.2[机械工程—光学工程] O562[理学—光学]