Synchronized distribution of quantum entanglement coexisting with high-rate, broadband classical optical communications over a real-world fiber link

Journal Article · Fri Jan 30 00:00:00 EST 2026 · No journal information

OSTI ID:3023411

Talcott, Gina M. ^[1]; Hess, Ahnnika I. ^[1]; d'Avossa, Laura ^[2]; Kohlert, Scott J. ^[3]; Yeh, Fei I. ^[4]; Chen, Jim Hao ^[4]; Mambretti, Joe J. ^[4]; Rambo, Tim M. ^[5]; Kanter, Gregory S. ^[6]; Thomas, Jordan M. ^[1]; Kumar, Prem ^[1]

---

1. Northwestern U.
2. Northwestern U.; Naples U.
3. Unlisted
4. Unlisted, US, IL
5. RadiaBeam Tech.
6. Northwestern U.; Euclid Techlabs, Solon

Compatibility with existing classical network infrastructure offers a scalable path towards deploying largescale quantum networks. Here, we demonstrate O-band polarization-encoded quantum entanglement distribution over an installed 24.4-km fiber while coexisting with a state-of-the-art fully-loaded C-band classical communications line system and a picosecond-level precision L-band synchronization signal. The classical system carries two 800-Gbps channels while the remainder of the C-band is filled with amplified spontaneous emission as is standard for such state-of-the-art communications systems. We examine the spontaneous Raman scattering spectrum generated from this broadband C-band light and offer insights into wavelength allocation for O-band quantum channels. Optimal wavelength selection and narrow filtering enable well-preserved Bell state fidelity when coexisting with 21.4-dBm aggregate launch power across the C-band suitable for 36 Tbps transmission. To the best of our knowledge, this is the first implementation of entanglement-based quantum communications between two remote nodes coexisting with independent classical communications traffic. We demonstrate coexistence of quantum entanglement with ultra-high power levels and record classical bandwidth, offering promise for real-world entanglement-based networking integrated within high-capacity communications infrastructure.

• Research Organization: Euclid Techlabs, Solon; Northwestern U.; Naples U.; Unlisted; Unlisted, US, IL; RadiaBeam Tech.
• Sponsoring Organization: US Department of Energy
• DOE Contract Number: 89243024CSC000002
• OSTI ID: 3023411
• Report Number(s): FERMILAB-PUB-26-0163-V; oai:inspirehep.net:3113865; arXiv:2602.00253
• Journal Information: No journal information, Journal Name: No journal information
• Country of Publication: United States
• Language: English