Tel Aviv, Israel, July 29, 2025 - PacketLight Networks, a leading provider of DWDM and OTN equipment, has successfully demonstrated quantum key distribution (QKD) over a 400G DWDM network in collaboration with NEC Corporation, a leader in the integration of IT and network technologies.

The joint demonstration, held at NEC’s laboratories in Japan, integrated NEC’s QKD system with PacketLight’s PL-4000M 600G Muxponder, showcasing a high-performance, quantum-safe network environment. The QKD transmission was carried over a separate dedicated fiber, operating alongside the main data link fiber. This separation ensures the integrity and stability of the quantum signals while maintaining full performance of the 400G data traffic over the DWDM infrastructure.

In this setup, the QKD channel was transmitted over a dedicated fiber, running in parallel to the DWDM data link. The dual-fiber configuration offers a scalable and cost-effective method for layering quantum security onto operational environments, paving the way for broader adoption of quantum-safe communications.

"The integration of NEC’s QKD technology with PacketLight's DWDM/OTN devices paves the way for enhanced secure data transmission," said Koby Reshef, CEO of PacketLight. "We take pride in our involvement in this cooperation and eagerly anticipate the market’s response to the new opportunities it presents."

"We are delighted to announce the successful completion of our joint demonstration with PacketLight," said Yoichiro Ito, the Director of Innovation Product Solutions Group, Defense Network Department, NEC. "NEC has a research base of QKD system in Japan and has led the advancement of it for over 20 years. Through this demonstration, we verified the interoperability of our QKD system with PacketLight’s equipment, which confirmed its applicability in more diverse usage scenarios. We will continue to strengthen our collaboration with partners and work toward creating even greater value."

Throughout the demonstration, the PacketLight and NEC teams validated system compatibility and network performance. The encrypted data link achieved full 100% throughput and consistently low latency, as verified with a 100GbE tester, reaffirming the efficiency and robustness of the integrated solution.

By demonstrating QKD over a separate fiber link, the collaboration proved that quantum technologies can be deployed in parallel to existing infrastructures without requiring costly or complex overhauls. This practical model allows for secure key exchange in real-world applications while preserving network simplicity and cost-efficiency.