Optical Confinement of a Bose-Einstein Condensate

Bose-Einstein condensates of sodium atoms have been confined in an optical dipole trap using a single focused infrared laser beam. This eliminates the restrictions of magnetic traps for further studies of atom lasers and Bose-Einstein condensates. More than 5×10⁶ condensed atoms were transferred into the optical trap. Densities of up to 3×10¹⁵cm^-3 of Bose condensed atoms were obtained, allowing for a measurement of the three-body loss rate constant for sodium condensates as K₃ = 1.1(3)×10^-30cm⁶s^-1. At lower densities, the observed 1/e lifetime was longer than 10 s. Simultaneous confinement of Bose-Einstein condensates in several hyperfine states was demonstrated.