  Global, secure quantum channels will require efficient distribution of
entangled photons. Long distance, low-loss interconnects can only be realized
using photons as quantum information carriers. However, a quantum light source
combining both high qubit fidelity and on-demand bright emission has proven
elusive. Here, we show a bright photonic nanostructure generating
polarization-entangled photon-pairs that strongly violates Bell's inequality. A
highly symmetric InAsP quantum dot generating entangled photons is encapsulated
in a tapered nanowire waveguide to ensure directional emission and efficient
light extraction. We collect $\sim$200 kHz entangled photon-pairs at the first
lens under 80\,MHz pulsed excitation, which is a 20 times enhancement as
compared to a bare quantum dot without a photonic nanostructure. The performed
Bell test using the Clauser-Horne-Shimony-Holt inequality reveals a clear
violation ($S_{\text{CHSH}}>2$) by up to 9.3 standard deviations. By using a
novel quasi-resonant excitation scheme at the wurtzite InP nanowire resonance
to reduce multi-photon emission, the entanglement fidelity
($F=0.817\,\pm\,0.002$) is further enhanced without temporal post-selection,
allowing for the violation of Bell's inequality in the rectilinear-circular
basis by 25 standard deviations. Our results on nanowire-based quantum light
sources highlight their potential application in secure data communication
utilizing measurement-device-independent quantum key distribution and quantum
repeater protocols.
