  We present a 1 GHz-clocked, maximally entangled and on-demand photon pair
source based on droplet etched GaAs quantum dots using two-photon excitation.
By employing these GaP microlensenhanced devices in conjunction with their
substantial brightness, raw entanglement fidelities of up to $0.95 \pm 0.01$
and post-selected photon indistinguishabilities of up to $0.93 \pm 0.01$, the
suitability for quantum repeater based long range quantum entanglement
distribution schemes is shown. Comprehensive investigations of a complete set
of polarization selective two-photon correlations as well as time resolved
Hong-Ou-Mandel interferences facilitate innovative methods that determine
quantities such as photon extraction and excitation efficiencies as well as
pure dephasing directly - opposed to commonly employed indirect techniques.
