Satellite Quantum Communication Using Narrow-Linewidth Atomic Line Filters

ABSTRACT: Physical Sciences Inc. (PSI) proposes to develop a free-space quantum key distribution link based on a narrow-linewidth atomic line filter in the receiver station. The improved spectral filtering of the atomic filter will improve the signal-to-noise ratio of the quantum communication link by increased solar background rejection, enabling both day and nighttime operation of a long-distance free-space quantum key distribution link between a satellite and an Earth-based ground station. In the Phase I program, PSI will develop and characterize the filter throughput and bandwidth under representative operational conditions. The outcome of the proposed work will be a characterization of the performance improvements of a quantum communication link based on a narrow-linewidth atomic line filter in the receiver. In the Phase II program, PSI will develop a portable transmitter and receiver module and characterize a free-space quantum key distribution link. BENEFIT: Quantum communication promises an unconditionally secure method for information transfer. Military, financial, medical, and other institutions with sensitive data will benefit from practical improvements to quantum communication links.