Near perfect two-photon interference out a down-converter on a silicon photonic chip

Abstract

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 (${\chi }^{(2)}$) 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 $\mu$W pump power. Remarkably, we report two-photon interference with near-perfect visibility of 99.36$\pm 1.94\%$, 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.

References in corpus (5)

• Chip-based photon quantum state sources using nonlinear optics
• Silicon Quantum Photonics
• Quantum photonics at telecom wavelengths based on lithium niobate waveguides
• An integrated source of spectrally filtered correlated photons for large scale quantum photonic systems
• Time-bin entangled photon pair generation from Si micro-ring resonator