  We report on the observation of bright emission of single photons under
pulsed resonance fluorescence conditions from a single quantum dot (QD) in a
micropillar cavity. The brightness of the QD fluorescence is greatly enhanced
via the coupling to the fundamental mode of a micropillar, allowing us to
determine a single photon extraction efficiency of $(20.7\pm0.8)~\%$ per linear
polarization basis. This yields an overall extraction efficiency of
$(41.4\pm1.5)~\%$ in our device. We observe the first Rabi-oscillation in a
weakly coupled quantum dot-micropillar system under coherent pulsed optical
excitation, which enables us to deterministically populate the excited QD
state. In this configuration, we probe the single photon statistics of the
device yielding $g^{(2)}(0)=0.072\pm0.011$ at a QD-cavity detuning of
$75~\mu$eV.
