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arXiv:2401.15882 · Optica Quantum

Space-division multiplexed phase compensation for quantum communication: concept and field demonstration

Riku Maruyama, Daisuke Yoshida, Koji Nagano, Kouyou Kuramitani, Hideyo Tsurusawa, Tomoyuki Horikiri

Published Feb 11, 2025• 3 citations

Abstract

Phase-sensitive quantum communication has received considerable attention to overcome the distance limitation of quantum communication. A fundamental problem in phase-sensitive quantum communication is to compensate phase drift in an optical fiber channel. A combination of time-, wavelength-, and space-division phase compensation can improve the phase stability of the optical fiber. However, the existing phase compensations have used only time- and wavelength-division compensation. Here, we demonstrate space-division multiplexed phase compensation in the Osaka metropolitan networks. Our compensation scheme uses two neighboring fibers, one for quantum communication and the other for sensing and compensating the phase drift. Our field investigations confirm the correlation of the phase drift patterns between the two neighboring fibers. Thanks to the correlation, our space-division multiplexed phase compensation significantly reduces the phase drift and improves the quantum bit error rate. Hence, our experimental study has established the space-division multiplexed phase compensation scheme. We also propose a hybrid scheme of space-wavelength-time-division multiplexed phase compensation for twin-field quantum key distribution and a quantum repeater system.

DOI: 10.1364/opticaq.525957

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