Experimental observation of optically trapped atoms

Abstract

We report the first observation of optically trapped atoms. Sodium atoms cooled below 10-3 K in "optical molasses" are captured by a dipole-force optical trap created by a single, strongly focused, Gaussian laser beam tuned several hundred gigahertz below the D1 resonance transition. We estimate that about 500 atoms are confined in a volume of about 103 m3 at a density of 1011-1012 cm-3. Trap lifetimes are limited by background pressure to several seconds. The observed trapping behavior is in good quantitative agreement with theoretical expectations. © 1986 The American Physical Society.