The U.S. Defense Advanced Research Projects Agency (DARPA) awarded Qunnect a contract to develop a next-generation rack for the vendor's Carina turnkey entanglement distribution platform.

The funding will advance Carina’s polarization-compensation technology, which continuously detects and corrects changes that could corrupt entangled-photon signals traveling over deployed telecom fiber.

Qunnect has Carina deployments operating on fiber networks in New York; Bozeman, Montana; Berlin; and Albuquerque. The Bozeman deployment is in partnership with Montana State University, while its Berlin network was established with Deutsche Telekom.

Sending quantum signals through existing fiber networks is challenging because temperature changes, vibrations, mechanical stress, and other environmental conditions alter the polarization of photons traveling through the fiber. For polarization-entangled photons, this drift can reduce fidelity and eventually make the entanglement unusable.

Carina’s controller monitors the channel and makes real-time corrections, effectively acting like noise-canceling headphones for the quantum signal.

In a February 2026 New York City trial, Qunnect and Cisco achieved polarization-entanglement fidelity of more than 99% while maintaining an entanglement-swapping rate of 5,400 photon pairs per hour across 11 miles (17.6 kilometers) of commercial fiber. The results demonstrated that automated polarization compensation could preserve high-fidelity entanglement under changing conditions on a live urban network.

The next-generation module is intended to provide the reliability and resilience needed to move quantum networks from time-limited demonstrations toward persistent operation.

Qunnect said governments increasingly view quantum networking as critical infrastructure, as defense agencies, telecommunications providers, and commercial organizations look beyond laboratory research toward systems capable of operating on deployed networks. The company argues that its existing installations give it an advantage as those organizations begin selecting technology partners.

“We made an early commitment to designing instruments that operate on the same infrastructure the world already uses,” Qunnect CEO Noel Goddard explained. “For the past five years, we focused on making quantum networking practical and we’ve validated it through deployments in cities and through partnerships with private industry and growing support from government agencies.”

Qunnect recently partnered with Monarch Quantum to develop smaller, manufacturable Carina variants for defense, telecom, edge, and space environments. The projects address two requirements for wider quantum network deployment: reliable operation on existing fiber and hardware suitable for constrained environments.

Quantum networks operating over existing fiber-optic infrastructure could eventually support secure communications and authentication, distributed quantum computing, precision timing, and sensing.

Qunnect has not disclosed terms of the DARPA contract.