Integrated entangled photon-pair sources are key elements for enabling large-scale quantum photonic solutions, and addresses the challenges of both scaling-up and stability. Here we report the first demonstration of an energy-time entangled photon-pair source based on spontaneous parametric down-conversion in silicon-based platform through an optically induced second-order (χ(2)) nonlinearity, ensuring type-0 quasi-phase-matching of fundamental harmonic and its second-harmonic inside the waveguide. The developed source shows a coincidence-to-accidental ratio of 1635 at 8 of μW pump power. Remarkably, we report two-photon interference with near-perfect visibility of 99.36±1.94%, showing high-quality photonic entanglement without excess background noise. This opens a new horizon for quantum technologies requiring the integration of a large variety of building functionalities on single chips.
@article{arxiv.2202.04316,
title = {Near perfect two-photon interference out a down-converter on a silicon photonic chip},
author = {Romain Dalidet and Florent Mazeas and Edgars Nitiss and Ozan Yakar and Anton Stroganov and Sébastien Tanzilli and Laurent Labonté and Camille-Sophie Brès},
journal= {arXiv preprint arXiv:2202.04316},
year = {2022}
}