Robust phase stabilization of a dark quantum channel over a 120 km deployed fiber link

Published

March 12, 2026

Author(s)

Daehyun Ahn, Ivan Burenkov, Jabir Marakkarakath Vadakkepurayil, Mheni Merzouki, Paulina Kuo, Abdella Battou, Thomas Gerrits, Sergey Polyakov

Abstract

We present a scalable solution for phase stabilization of dark metropolitan-scale fiber links using wavelength division multiplexing (WDM). We implement a combined feed-back and feed-forward phase stabilization for a target channel by combining error signals from two separate reference channels over a 120 km deployed aerial fiber link. Residual jitter in the dark channel is reduced by two orders of magnitude compared to a simple feedback strategy and reaches subfemtosecond RMS values. Observed cross-talk photon noise is ≈500 photons per second. This approach enables quantum network protocols for phase-sensitive entanglement distribution and quantum key distribution, coherent clock transfer, and coherent optical communication. Potentially, multiple dark target channels can be phase-stabilized without injecting additional reference channels.

Citation

Optica

Volume

13

Pub Type

Journals

Download Paper

https://doi.org/10.1364/OPTICA.586649

Local Download

Keywords

Phase stabilization, quantum network, dark fiber, quantum link, metropolitan fiber link, frequency-comb, ultra stable laser, phase noise, Allan deviation

Citation

Ahn, D. , Burenkov, I. , Marakkarakath Vadakkepurayil, J. , Merzouki, M. , Kuo, P. , Battou, A. , Gerrits, T. and Polyakov, S. (2026), Robust phase stabilization of a dark quantum channel over a 120 km deployed fiber link, Optica, [online], https://doi.org/10.1364/OPTICA.586649, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=960988 (Accessed March 21, 2026)