原子源的制备与相干性检测

利用不平衡三维磁光阱(3D-MOT)技术,制备了低速、高通量的连续型原子束。通过使一束冷却光沿着光传播方向形成"中空光束",在MOT中形成一对具有不平衡光辐射压力的对射光束,压力将MOT中冷却与陷俘的87 Rb原子云团从"中空光束"通道中推出产生连续出射的原子。形成的原子束具有一定的速度和速度分布,可反映原子束的相干性。对所制备原子束的相干性进行了测量和分析,结果表明,所产生的原子束的最可几速度约为12m/s,纵向速度分布约为3m/s,对应的德布罗意波波长约为0.4nm,带宽为0.1nm。通过光电倍增管(PMT)收集的荧光强度推算得原子束通量为108～109 atoms/s。

Preparation and coherent detection for a continuous source of atoms

We present an unbalanced three-dimensional(3D) magneto-optical trap(MOT) setup for the production of a continuous source of cold 87Rb atoms,which is cooled,trapped and pushed out by the MOT-generated radiation pressure difference employing a specially designed leak tunnel along one trapping laser beam.The coherence of the atomic beam is calculated with the velocity and the velocity spread which are obtained from the time-of-flight(TOM) signal.The experimental results show that an 87Rb beam with De Broglie wave length of 0.4 nm and bandwidth of 0.1 nm according to the most probable velocity of 12 m/s and a velocity spread of 3 m/s is generated with this method.And a flux of 108-109 atoms/s can be generated based on the measurement of the photomultiplier tube(PMT) signal from the source.