  We present an optical setup with focus-tunable lenses to dynamically control
the waist and focus position of a laser beam, in which we transport a trapped
ultracold cloud of 87-Rb over a distance of 28 cm. The scheme allows us to
shift the focus position at constant waist, providing uniform trapping
conditions over the full transport length. The fraction of atoms that are
transported over the entire distance comes near to unity, while the heating of
the cloud is in the range of a few microkelvin. We characterize the position
stability of the focus and show that residual drift rates in focus position can
be compensated for by counteracting with the tunable lenses. Beyond being a
compact and robust scheme to transport ultracold atoms, the reported control of
laser beams makes dynamic tailoring of trapping potentials possible. As an
example, we steer the size of the atomic cloud by changing the waist size of
the dipole beam.
