  In this chapter we review the use of semiconductor quantum dots as sources of
quantum light. Principally, we focus on resonant two-photon excitation, which
is a method that allows for on-demand generation of photon pairs. We explore
the advantages of resonant excitation and present a number of measurements that
were made in this excitation regime. In particular, we cover the following
topics: photon statistics, coherent manipulation of the ground-excited state
superposition, and generation of time-bin entangled photon pairs.
