  We investigate the multiphoton quantum dynamics of a leaking single-mode
quantized cavity field coupled with a resonantly driven two-level system
possessing permanent dipoles. The frequencies of the interacting subsystems are
being considered very different, e.g., microwave ranges for the cavity and
optical domains for the frequency of the two-level emitter, respectively. In
this way, the emitter couples to the resonator mode via its diagonal dipole
moments only. Furthermore, the generalized Rabi frequency resulting form the
external coherent driving of the two-level subsystem is assumed as well
different from the resonator's frequency or its multiples. As a consequence,
this highly dispersive interaction regime is responsible for the cavity
multiphoton quantum dynamics and photon conversion from optical to microwave
ranges, respectively.
