Generation of polarization-entangled photon pairs in a Bragg reflection waveguide

TL;DR

This paper reports the experimental generation of polarization-entangled photon pairs at 1550 nm using a Bragg reflection waveguide in AlGaAs, demonstrating high entanglement quality and Bell inequality violation, advancing integrated quantum photonics.

Contribution

It introduces a novel on-chip source of polarization-entangled photons using spontaneous parametric down-conversion in an AlGaAs waveguide, with high entanglement visibility and Bell violation.

Findings

Photon pairs show >90% visibility in multiple polarization bases

Bell inequality violated by more than 3 standard deviations

Demonstrates a promising integrated source for quantum communication

Abstract

We demonstrate experimentally that spontaneous parametric down-conversion in an AlGaAs semiconductor Bragg reflection waveguide can make for paired photons highly entangled in the polarization degree of freedom at the telecommunication wavelength of 1550 nm. The pairs of photons show visibility higher than 90% in several polarization bases and violate a Clauser-Horne-Shimony-Holt Bell-like inequality by more than 3 standard deviations. This represents a significant step toward the realization of efficient and versatile self pumped sources of entangled photon pairs on-chip.