  The integration of on-demand quantum emitters into photonic integrated
circuits (PICs) has drawn much of attention in recent years, as it promises a
scalable implementation of quantum information schemes. A central property for
several applications is the indistinguishability of the emitted photons. In
this regard, GaAs quantum dots (QDs) obtained by droplet etching epitaxy show
excellent performances with visibilities close to one for both individual and
remote emitters. Therefore, the realization of these QDs into PICs is highly
appealing. Here, we show the first implementation in this direction, realizing
the key passive elements needed in PICs, i.e. single-mode waveguides (WGs) with
integrated GaAs-QDs, which can be coherently controlled, as well as
beamsplitters. We study both the statistical distribution of wavelength,
linewidth and decay times of the excitonic line of multiple QDs, as well as the
quantum optical properties of individual emitters under resonant excitation.
Here, we achieve single-photon purities as high as
$1-\text{g}^{(2)}(0)=0.929\pm0.009$ as well as two-photon interference
visibilities of up to V$_{\text{TPI}}=0.939\pm0.004$ for two consecutively
emitted photons.
