The U.S. Department of Energy’s Brookhaven National Laboratory and Stony Brook University have opened the first permanent free-space optical quantum link in the United States, transmitting entangled photons across 13 miles of Long Island atmosphere between two rooftop observatories built specifically for the purpose.
Ribbon Cut On The Quantum Lighthouse
At a ceremony on Friday, August 21, DOE Under Secretary for Science Darío Gil cut a ribbon blocking the receiving aperture of Brookhaven’s Quantum Lighthouse, letting photons from Stony Brook’s Quantum Watchtower reach the detector. Officials from New York State, the DOE and both institutions were on hand. The daytime demonstration transmitted quantum-encoded photons through 21 kilometres of open air between fibers only about 5 microns wide — less than a tenth of a human hair.
Entangled Photons Across 21 Kilometres
Two days earlier, at 12:26 a.m. ET on Wednesday, August 19, the team recorded the arrival of entangled photon pairs sent from the Watchtower across the new FSO link during a nighttime run when background light is lower. The link plugs into the eight-node, 161-mile fiber-optic quantum network already running between Long Island and the New York metro area, giving that infrastructure a wireless leg for the first time.
A Roadmap Toward Yale, The Long Island Sound And Satellites
“In our new quantum wireless links, we are exploring the use of infrared wavelengths that are native to quantum processors and related technologies,” Stony Brook Quantum Institute director Eden Figueroa said, calling it “a direct route to create entangled atomic systems across long distances.” A third optical facility at Yale University in New Haven is complete, and the collaboration is preparing to establish a 30-mile entanglement link across the Long Island Sound. Brookhaven’s Gabriella Carini said the ultimate goal is transmitting quantum information to orbiting satellites for global reach.
The project draws heavily on astronomy expertise: Brookhaven’s telescope group built the adaptive-optics rigs that let single photons survive atmospheric turbulence. The work fits into DOE’s Genesis Mission agenda for interconnected quantum, AI and high-performance computing. For related coverage, see Quantum X Labs’ AI decoder benchmark, IBM’s modular cryogenic quantum link, and Crypto4A’s FIPS 140-3 quantum-safe HSM validation.
Reporting based on coverage from Brookhaven National Laboratory, Stony Brook University Newsroom and the Quantum Computing Report.