Active polarization control for quantum communication in long-distance optical fibers with shared telecom traffic

TL;DR

This paper demonstrates a method for actively stabilizing polarization in long-distance quantum communication fibers that also carry classical telecom traffic, ensuring stable quantum and classical data transmission over 23 km.

Contribution

It introduces a wavelength multiplexed active polarization stabilization technique compatible with existing telecom traffic in long-distance fibers.

Findings

Successful 6-hour continuous operation maintaining polarization stability

Quantum signals transmitted in both directions with preserved polarization

Classical feedback channel remained error-free during experiments

Abstract

We experimentally demonstrate the compatibility of wavelength multiplexed active polarization stabilization for quantum communication in an optical fiber carrying telecom traffic. One of the feedback control channels contains a 9.953 Gb/s data stream generated from a BER meter. We verify the ability to transmit single-photons in the two opposite directions of a 23 km optical fiber spool, while maintaining their state of polarization stable and a classical BER in the feedback channel error-free, during 6 hours of continuous operation.