Optically confined Bose-Einstein condensates

With an optical dipole trap it is possible to confine Bose-Einstein condensates in different hyperfine states and in arbitrary magnetic bias fields, thus overcoming two major limitations of magnetic traps. In this rewiev paper we characterize the properties of such a dipole trap and we summarise experiments which made use of the new experimental possibilities, including the reversible formation of a Bose-Einstein in condensate, the observation of Feshbach resonances in sodium and the ground state properties of spinor Bose-Einstein condensates. Finally, we present some new results on the shape of magnetically trapped and ballistically expanding condensates.