Brookhaven Establishes First Permanent 13-Mile Free-Space Quantum Link
Updated
Updated · Newswise · Aug 22
Brookhaven Establishes First Permanent 13-Mile Free-Space Quantum Link
3 articles · Updated · Newswise · Aug 22
Summary
Brookhaven Lab said its Quantum Lighthouse has now made the 13-mile entangled-photon connection to Stony Brook the first permanent free-space optical quantum link.
The link adds a wireless leg to the nation’s 161-mile quantum network, letting researchers move quantum information beyond fiber using telescopes and adaptive optics.
Those optics must correct heavy near-ground turbulence thousands of times per second, expanding a roughly 5-micron fiber signal to a 25-inch beam and refocusing it into fiber at the far end.
Operations are initially limited to clear nights because fog blocks the line of sight and sunlight raises turbulence and background noise, though the team aims for all-weather, daytime transmission.
A third node at Yale is due to open soon for a 30-mile Long Island Sound link, and the setup is also intended as a testbed for future quantum-satellite networking.