  We propose a robust scheme to generate multi-photon Fock states in an
atom-maser-cavity system using adiabatic passage techniques and topological
properties of the dressed eigenenergy surfaces. The mechanism is an exchange of
photons from the maser field into the initially empty cavity by bichromatic
adiabatic passage. The number of exchanged photons depends on the design of the
adiabatic dynamics through and around the conical intersections of dressed
eigenenergy surfaces.
