Optical fibre-based single photon source using InAsP quantum dot nanowires and gradient-index lens collection

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.

Automated summary

The study introduces a compact, fibre-coupled single photon source using gradient-index lenses and an InAsP quantum dot, providing stable, high brightness fibre-coupled single photons. By using pulsed excitation, researchers achieved an on-demand operation with 98.5% single photon purity. Additionally, plug and play operation was demonstrated using room temperature photoluminescence for alignment.