Experimental space-division multiplexed polarization-entanglement distribution through 12 paths of a multicore fiber

TL;DR

This paper demonstrates the distribution of polarization-entangled photon pairs through a multicore fiber using space-division multiplexing, achieving high stability and capacity for quantum communication networks.

Contribution

It introduces a novel SDM approach for quantum entanglement distribution over multicore fibers with high stability and scalability.

Findings

Successful distribution of entangled photons over 12 channels

High polarization visibility and Bell inequality violation

Stable operation over 24 hours without active stabilization

Abstract

The development and wide application of quantum technologies highly depend on the capacity of the communication channels distributing entanglement. Space-division multiplexing (SDM) enhanced channel capacities in classical telecommunication and bears the potential to transfer the idea to quantum communication using current infrastructure. Here, we demonstrate an SDM of polarization-entangled photons over a 411m long 19-core multicore fiber distributing polarization-entangled photon pairs through up to 12 channels simultaneously. The quality of the multiplexed transfer is evidenced by high polarization visibility and CHSH Bell inequality violation for each pair of opposite cores. Our distribution scheme shows high stability over 24 hours without any active polarization stabilization and can be effortlessly adapted to a higher number of channels. This technique increases the quantum-channel capacity and allows the reliable implementation of quantum networks of multiple users based on a single entangled-photon pair source.