Theory of strong outcoupling from Bose-Einstein condensates

We study the dynamics of a magnetically trapped Bose-Einstein condensate in the presence of an external electromagnetic-field coupling trapped, untrap ped, and antitrapped Zeeman sublevels. For large condensates an approximate analytical solution of the coupled Gross-Pitaevskii equations is given in the regime of strong outcoupling. The theory is developed for the cases of rf outcoupling within a hyperfine manifold of states, microwave outcoupling connecting states in two different hyperfine manifolds, and Raman outcoupl ing. [S1080-2947(99)06207-1].