PMD-Tolerant 20 krad/s Endless Polarization and Phase Control for BB84-Based QKD with TDM Pilot Signals

TL;DR

This paper demonstrates a TDM-based polarization and phase control system for BB84 quantum key distribution that tolerates high polarization mode dispersion and maintains stable polarization and phase over long fiber links.

Contribution

It introduces a TDM-based control method with high PMD tolerance and fast tracking speed, enabling stable QKD over 63 km fiber links.

Findings

35 ps PMD tolerance achieved

20 krad/s tracking speed demonstrated

Stable polarization and phase control over 63 km fiber

Abstract

TDM-based polarization and differential phase control with 35ps PMD tolerance and 20krad/s tracking speed is demonstrated. 600ns intervals are reserved for QKD and for 0{\deg}- and 45{\deg}-polarized pilot signals. ECLs are modulated directly, with high extinction. Power budget is 17dB, fiber length is 63km.