Silicon-on-insulator integrated source of polarization-entangled photons

TL;DR

This paper demonstrates an experimental silicon-on-insulator device that generates polarization-entangled photons at telecom wavelengths, achieving high fidelity and Bell inequality violation, advancing integrated quantum photonics.

Contribution

It introduces a novel 2D coupler for converting path entanglement into polarization entanglement in silicon photonics, with experimental validation.

Findings

Fidelity of 88% with a non-maximally entangled state.

Bell inequality violation with S=2.37±0.19.

Successful generation of polarization-entangled photons in silicon-on-insulator waveguides.

Abstract

We report the experimental generation of polarization-entangled photons at telecommunication wavelengths using spontaneous four-wave mixing in silicon-on-insulator wire waveguides. The key component is a 2D coupler that transforms path entanglement into polarization entanglement at the output of the device. Using quantum state tomography we find that the produced state has fidelity 88% with a pure non-maximally entangled state. The produced state violates the CHSH Bell inequality by S=2.37\pm0.19.