Atom Funnel with a Micron-Sized Outlet Using Evanescent Light

We process a silicon-on-insulator substrate into a funnel structure with a 2-\mbox{$\mu$m}-side square-shaped outlet by photolithography, anisotropic chemical etching, sputtering, and drilling with a focused ion beam. The funnel element is designed to generate a cold atomic beam with a high flux intensity of 1 atom/nm 2 $\cdot$s using repulsive evanescent light. The evanescent light is produced in TE modes propagating through a 1-\mbox{$\mu$m}-thick TiO 2 layer deposited on the slope faces in the case of coupling near-infrared lights for collecting Rb atoms released from a magneto-optical trap. The decay length of evanescent light is measured with a fiber probe in the collection mode.