All-optical Bose-Einstein condensate experiment

All optical traps for BEC have many advantages over those of conventional magnetic trap geometries, including simplicity of the setup, insensitivity to the spin state, and high BEC production rate. Furthermore, evaporative cooling is achieved by simply reducing the intensity of the trapping dipole beams.

The aim for this apparatus was to create an all-optical 87Rb Bose-Einstein condensate experiment. This system starts with a standard magneto optical trap (MOT) loaded in our vacuum chamber from a rubidium dispenser. After a compression and optical molasses stage, the atoms are loaded into a single beam dipole trap overlapping the MOT, formed by a laser operating at 1064 nm, with a beam waist of 27 μm and power of 14W. Our initial conditions in the single dipole trap are ~3 × 10⁶ atoms, with a temperature of ~250 μK. A first stage of evaporative cooling is performed by lowering the trapping intensity in the single beam. A secondary orthogonal beam is then ramped up in power, compressing the cloud and increasing the collision rate, before both beams are lowered in intensity.

The experiment was retired in 2012 and made room for the Spinor BECs in Toroidal Traps apparatus.