  We propose a method to exploit high finesse optical resonators for light
assisted coherent manipulation of atomic ensembles, overcoming the limit
imposed by the finite response time of the cavity. The key element of our
scheme is to rapidly switch the interaction between the atoms and the cavity
field with an auxiliary control process as, for example, the light shift
induced by an optical beam. The scheme is applicable to many different atomic
species, both in trapped and free fall configurations, and can be adopted to
control the internal and/or external atomic degrees of freedom. Our method will
open new possibilities in cavity-aided atom interferometry and in the
preparation of highly non-classical atomic states.
