  Developing coherent excitation methods for quantum emitters which enable high
brightness, good single-photon purity and high indistinguishability of the
emitted photons has been a key challenge in the past years. While many methods
have been proposed and explored, they all have specific advantages and
disadvantages. In this letter, we investigate the dynamics of the recent
swing-up scheme as an excitation method for a two-level system and its
performance in single-photon generation. By applying two far red-detuned laser
pulses, the two-level system can be prepared in the excited state with
near-unity fidelity. We demonstrate the successful functionality and the
coherent character of this technique using semiconductor quantum dots.
Moreover, we explore the multi-dimensional parameter space of the two laser
pulses to study the impact on the excitation fidelity. Finally, we investigate
the performance of the scheme as an excitation method for generation of
high-quality single photons. We find that the swing-up scheme itself works well
and exhibits nearly perfect single-photon purity, while the observed
indistinguishability in our sample is limited by the influence of the
inevitable high excitation powers on the semiconductor environment of the
quantum dot.
