Quantum Network Facility
Free Space Optical Link
A Brookhaven Lab-Stony Brook University free space link will provide a direct, site-to-site entanglement distribution channel independent of underground infrastructure. A rooftop construction effort is in progress and the optical system is in active development, with a sub-scale pathfinder system having already demonstrated coupling single-mode fiber to free space and back with excellent efficiency at the 795 nm Rubidium wavelength.
Free space link demonstrator on mobile experiment platform.
The rooftop emitter and receiver stations will be configured to operate at both the fiber telecom C-band and at 795 nm. They will employ telescope apertures between .4m and .7m for efficient transmission over the 20.5km line of sight. The current mobile free space link platforms use 10” reflecting telescopes and demonstrate beam injection, separation, automatic alignment, and atmospheric correction (adaptive optics).
Free space link demonstrators.
The full-scale free space receiver at Brookhaven National Laboratory was conceived as a rooftop lab. This location will allow ongoing optimization of the advanced, triple-conjugate, adaptive optics and extensibility of other systems which automate the photon distribution system to provide entanglement as a service. Site access for this rooftop node has been established and installation of the lab-like enclosure (colloquially known as the “shack”) is forthcoming.
