Abstract
Large-scale integrated sources of quantum light are enabling ingredients for the future of photonic quantum technologies. For such platforms, sources based on electrical injection are of value for their turnkey operation, as they do not rely on bulky off-chip sources to achieve quantum nonlinear conversion. This work presents the first demonstration of a source of entangled photons fully contained in a single waveguide. Our source is based on a single battery-powered Bragg reflection waveguide diode laser producing two indistinguishable sources of ultra-broadband polarization-entangled photons. The output state of our device has a Bell-state fidelity of 86.3% without accidental subtraction, a high entangled pair generation rate of 1.16 × 106 (pairs)/(s ⋅ mW ⋅ facet), and an ultra-broadband entangled photon pair bandwidth >5.22 THz. Our approach yields scalable, compact, low-power, and stable sources of polarization-entangled photons, needed for real-world applications of quantum communications and network systems.
| Original language | English |
|---|---|
| Article number | 128 |
| Journal | npj Quantum Information |
| Volume | 11 |
| Issue number | 1 |
| DOIs | |
| State | Published - Dec 2025 |
Funding
The authors would like to acknowledge the Quantum Nano Fabrication and Characterization Facility at the University of Waterloo, where fabrication of the laser diodes was performed. We acknowledge the support of the Natural Sciences and Engineering Research Council of Canada (NSERC). Z.M.L. would like to thank Ryan Marchildon for his early guidance on the project.