  The spectral and temporal response of a set of $N$ quantum emitters embedded
in a photonic cavity is studied. Quantum mechanically, such systems can be
described by the Tavis-Cummings (TC) model of $N$ two-level systems coupled to
a single light mode. Here we compare the full quantum solution of the TC model
for different numbers of quantum emitters with its semiclassical limit after a
pulsed excitation of the cavity mode. Considering different pulse amplitudes,
we find that the spectra obtained from the TC model approach the semiclassical
one for an increasing number of emitters $N$. Furthermore they match very well
for small pulse amplitudes. While we observe a very good agreement in the
temporal dynamics for photon numbers much smaller than $N$, considerable
deviations occur in the regime of photon numbers similar to or larger than $N$,
which are linked to collapse and revival phenomena. Wigner functions of the
light mode are calculated for different scenarios to analyze the quantum state
of the light field. We find strong deviations from a coherent state even if the
dynamics of the expectation values are still well described by the
semiclassical limit. For higher pulse amplitudes Wigner functions similar to
those of Schr\"odinger cat states between two or more quasi-coherent
contributions build up.
