Laser Cooling and Trapping of Alkaline Earth Atoms

Abstract
Characteristics of laser trapping of Ca and Sr are experimentally studied and discussed. The lifetime of the trap is found to be limited by accumulation of the population in the 3P2 state, not by the decay 1P11D2. This result allows us to generate a continuous free-falling flow of ultra-cold ground state atoms which is useful for ultra-high resolution spectroscopy. Effects of an optical pumping laser which recycles the 1D2 population in Sr are investigated.