Song Ningfang, Hu Di, Xu Xiaobin, Li Wei, Lu Xiangxiang, Song Yitong
Department of Instrumentation Science and Opto-electronics Engineering, Beihang University, Beijing 100191, China.
Sensors (Basel). 2018 Feb 28;18(3):717. doi: 10.3390/s18030717.
The primary purpose of this study is to investigate the influence of the vertical guiding laser beam waist on cold atom guiding efficiency. In this study, a double magneto-optical trap (MOT) apparatus is used. With an unbalanced force in the horizontal direction, a cold atomic beam is generated by the first MOT. The cold atoms enter the second chamber and are then re-trapped and cooled by the second MOT. By releasing a second atom cloud, the process of transferring the cold atoms from MOT to the dipole trap, which is formed by a red-detuned converged 1064-nm laser, is experimentally demonstrated. And after releasing for 20 ms, the atom cloud is guided to a distance of approximately 3 mm. As indicated by the results, the guiding efficiency depends strongly on the laser beam waist; the efficiency reaches a maximum when the waist radius (₀) of the laser is in the range of 15 to 25 μm, while the initial atom cloud has a radius of 133 μm. Additionally, the properties of the atoms inside the dipole potential trap, such as the distribution profile and lifetime, are deduced from the fluorescence images.
本研究的主要目的是探究垂直引导激光束腰对冷原子引导效率的影响。在本研究中，使用了双磁光阱（MOT）装置。由于在水平方向存在不平衡力，第一个MOT产生冷原子束。冷原子进入第二个腔室，然后被第二个MOT重新捕获并冷却。通过释放第二个原子云，实验证明了冷原子从MOT转移到由红失谐会聚1064纳米激光形成的偶极阱的过程。并且在释放20毫秒后，原子云被引导至约3毫米的距离。结果表明，引导效率强烈依赖于激光束腰；当激光的腰半径（₀）在15至25微米范围内时，效率达到最大值，而初始原子云的半径为133微米。此外，从荧光图像中推导出偶极势阱内原子的性质，如分布轮廓和寿命。
