  We present a compact, fibre-coupled single photon source using gradient-index
(GRIN) lenses and an InAsP semiconductor quantum dot embedded within an InP
photonic nanowire waveguide. A GRIN lens assembly is used to collect photons
close to the tip of the nanowire, coupling the light immediately into a single
mode optical fibre. The system provides a stable, high brightness source of
fibre-coupled single photons. Using pulsed excitation, we demonstrate on-demand
operation with a single photon purity of 98.5% when exciting at saturation in a
device with a source-fibre collection efficiency of 35% and an overall single
photon collection efficiency of 10%. We also demonstrate "plug and play"
operation using room temperature photoluminescence from the InP nanowire for
room temperature alignment.
