Two-photon excitation of launched cold atoms in flight

摘要: We demonstrate two-photon bi-chromatic excitation of cold rubidium atoms in flight, using the pathway 5S1/2→5P3/2→5D5/2 with two resonant photons. In our experiment, Rb85 are laser-cooled a magneto-optical trap and launched upward discrete clouds controllable vertical speed 7.1±0.6  m/s velocity spread that is less than 10% launch speed. Outside cooling beams, as high 14 mm above original center trap, illuminated simultaneously by spatially localized horizontal beams at 780 nm (5S1/2→5P3/2) 776 (5P3/2→5D5/2). monitor transmission 780-nm beam over range intensities 776-nm light. As moving cloud passes we observe much 97.9±1.2% when rate absorption 5S1/2 5P3/2 states depopulated, compared to 87.6±0.9% if only present. This demonstrates cold-atom source narrow spread, foundation for three-photon Rydberg states.