  The origin of the emission within the optical mode of a coupled quantum
dot-micropillar system is investigated. Time-resolved photoluminescence is
performed on a large number of deterministically coupled devices in a wide
range of temperature and detuning. The emission within the cavity mode is found
to exhibit the same dynamics as the spectrally closest quantum dot state. Our
observations indicate that fast dephasing of the quantum dot state is
responsible for the emission within the cavity mode. An explanation for recent
photon correlation measurements reported on similar systems is proposed.
