Dark Optical Traps for Cold Atoms

Wolfgang Ketterle, David E. Pritchard

Nir Davidson

Dark optical traps use repulsive light forces to confine atoms mostly in the dark where their interaction with the trapping light is largely reduced, to enable long coherence times of the trapped atoms combined with tight confinement. We report on single-beam dark optical traps for ultra-cold atoms. These traps were used to demonstrate new spectroscopic and dynamical effects of the trapped atoms, including the observation of regular and chaotic motion in so called optical "billiards."

M. L. Miguez, Ph. W. Courteille

Harold J. Metcalf, P. van der Straten

S. A. Kulin, S. Aubin, Steven Christe +3 more

We present an optical trap for atoms which we have developed for precision spectroscopy measurements. Cold atoms are captured in a dark region of space inside a blue-detuned hollow laser beam formed by an axicon. We analyse the light potential in a ray optics picture and experimentally demonstrate trapping of laser-cooled metastable xenon atoms.

Rudolf Grimm, Matthias Weidemüller, Yuri B. Ovchinnikov