Enhancement of Transfer Efficiency of Cold Atoms Using an Optical Guiding Laser Beam

We transfer cold ⁸⁷Rb atoms from a vapour cell chamber to a spatially separated UHV magneto-optical trap (MOT) with the assistance of a red-detuned optical guiding beam and a normal push beam. Efficient optical guiding of the cold atoms is observed within a small detuning window. A pulsed optical guiding beam enhances the transfer efficiency and hence allows us to collect more atoms in UHV MOT in a shorter time, which is favourable for our experiment of achieving Bose--Einstein condensates (BEC). Besides the easy operation, another advantage of this optical guiding technique is also demonstrated such that slower atomic beams may be efficiently transferred along horizontal direction. This study is a direct application of the optical guiding technique as a powerful tool.