Adaptive-Optics-Enabled Quantum Communication: A Technique for Daytime Space-To-Earth Links
Mark T. Gruneisen, Mark Eickhoff, Scott Newey, Kurt E. Stoltenberg, Jeffery F. Morris, Michael Bareian, Mark Anglin Harris, Denis W. Oesch, Michael D. Oliker, Michael Flanagan, Brian T. Kay, J. Schiller, R. Nicholas Lanning
Abstract
Robust quantum channels between satellites and Earth are essential for the anticipated quantum Internet, but remain challenging in daylight, when background photons vastly outnumber qubit photons. Insufficient understanding of atmospheric propagation and turbulence compensation has led to approaches based on prohibitively narrow spectral filtering and unnecessarily low channel efficiencies. This field experiment uses adaptive optics to maximize efficiency while spatially filtering sky noise at the theoretical limit, enabling quantum communication over the daytime sky hemisphere. Requirements for spectral filtering are relaxed enough to accommodate present-day sources of entangled photons.