Description: The overall goal of this NASA effort is to develop and deliver efficient, single-pass quantum optical waveguide sources generating high purity hyper-entangled photon pairs for use in high-rate long-distance links. The new devices will produce hyper-entangled photon pairs with high efficiency, pure spectral properties, and low attenuation, providing the key technology required for deployment of ground-to-space links and future construction of a global quantum network. The waveguide-based technology is compact, robust, and power efficient for deployment on space-based platforms such as the International Space Station.

Benefits: To provide reliably secure communications, development of practical quantum optical devices for ground-to-space quantum key distribution is a necessity. The proposed technology offers a path to provably, unconditionally secure quantum encryption meeting future NASA security requirements. A space-based implementation of the technology may also answer important questions in fundamental physics by testing the properties of quantum entanglements over much greater distances than ever before, and due to earth's gravitational curvature may provide an insight to the relationship between gravity and quantum physics.

Quantum-based communication is of prime interest to corporations and government agencies with high security requirements. In cases where classical schemes are not considered trustworthy, key distribution by courier is typically used. Unlike human courier networks, quantum cryptography has the ability to detect interception of the key, has greater reliability and operating costs, and is automatic and instantaneous. For long distance quantum communication to be practical, ground-to-space links are a necessity due to the current limitations of optical fiber and photon detectors in ground-to-ground links. Additionally, the path to creating entangled photon sources that are as ubiquitous as diode lasers are today has implications in whole new arenas of economic development in addition to national security.