  If a two-level system coupled to a single-mode cavity is strongly driven by
an external laser, instead of a continuous accumulation of photons in the
cavity, oscillations in the mean photon number occur. These oscillations
correspond to peaks of finite width running up and down in the photon number
distribution, reminiscent of wave packets in linear chain models. A single wave
packet is found if the cavity is resonant to the external laser. Here, we show
that for finite detuning multiple packet structures can exist simultaneously,
oscillating at different frequencies and amplitudes. We further study the
influence of dissipative effects resulting in the formation of a stationary
state, which depending on the parameters can be characterized by a bimodal
photon number distribution. While we give analytical limits for the maximally
achievable photon number in the absence of any dissipation, surprisingly,
dephasing processes can push the photon occupations towards higher photon
numbers.
