各向同性激光冷却的快速冷原子密度测量

Method for Fast Measuring Cold Atom Density by Isotropic Laser Cooling

在某些冷原子实验中,需要提前测定冷原子的密度分布并为后续实验提供数据支持,以前的手动方法已不再适用,针对该问题提出了一种新型的冷原子密度分布测量方法,可在单个冷原子制备周期内实现对原子密度分布的测量。新的方法利用一对反亥姆霍兹线圈与一对亥姆霍兹线圈分别产生梯度磁场和偏置磁场,通过调节亥姆霍兹线圈电流,即可改变总磁场零点的位置,进而影响不同位置处的原子对探测光吸收的贡献,最终实现对原子密度分布的测量。在理论上分析了该方法的可行性,并提出了快速冷原子密度测量的实验方案。

In some coldatom experiments,it is necessary to measure the density distribution of cold atoms in advance and provide data support for subsequent experiments.The previously established manual method is no longer suitable for such experiments.In this study,we propose a new method for measuring the density distribution of cold atoms during a single preparation period of cold atoms.The proposed method uses a pair of antiHelmholtz coils and a pair of Helmholtz coils to generate gradient and bias magnetic fields,respectively.By adjusting the Helmholtz coil current,the position of zero point of the total magnetic field can be changed,the contribution of atoms at different positions to the probe light absorption can be affected,and finally,the atomic density distribution can be measured.The feasibility of this method is analyzed theoretically,and an experimental scheme for fast cold atom density measurements is proposed.