Cold-atom output from a near-field optical funnel

We demonstrated an atom funnel using blue-detuned near-field light. Cold Rb atoms generated by a magneto-optical trap (MOT) were introduced into the funnel and the output atoms were counted by an accumulative MOT detection system. The number of cold Rb atoms outputted from a 200-μm exit hole was maximal at a blue detuning of 1.2 GHz under Sisyphus cooling. The flux intensity was estimated to be 10⁵ atoms/cm²s. To increase the flux intensity up to 10¹³ atoms/cm²s, we made an atom funnel with a 2-μm exit hole.