All-optical Bose–Einstein condensation in a 1.06 μm dipole trap

We report the all-optical production of a 87Rb Bose–Einstein condensate (BEC) in a simple 1.06 μm dipole trap experiment. We load a single beam dipole trap directly from a magneto-optic trap (MOT). After evaporation in the single beam, a second crossed beam is used for compression. The intensity in both beams is then reduced for evaporation to BEC. We obtain a BEC with 3.5 × 104 atoms after 3 s of total evaporation time. We also give a detailed account of the thermal distribution in cross beam traps. This account highlights the possible difficulties in using shorter wavelength lasers to condense all optically.

Research Highlights
► We discuss issues with thermalization in crossed short wavelength traps.
► We present a simple method for all-optical production of Bose-Einstein condensate.