Grant: Research Tools and Instruments - Category 1 (<$150,000)

The proposed research program will expand the limits for the distances of ground based quantum communications. Current systems can reach about 200 kms in point-to-point fibre links. This research will explore how quantum communications and entanglement can be achieved much further, possibly up to 500km, and how to interconnect both the free space link to a satellite and a fibre based link on the ground using entangling measurements. This research is relevant for interconnecting the envisioned satellite ground stations with user locations, but avoiding the need to trust the ground station facility. This work is important because such ground stations would ideally be located at good optical sites, which are usually in remote locations which can be several hundred kms from major cities. Furthermore, quantum communications and entanglement at distances of several hundred kms would be very interesting for interconnecting locations between large cities by itself. The requested equipment includes the required laser systems and optical components to implement novel entangled photon sources and quantum relay schemes that will enable to reach for up to 500 km quantum communications. This equipment is crucial to further substantiate and support our efforts towards achieving global quantum communications, by establishing quantum entanglement and communications between urban areas such as cities, and remote optical satellite ground stations.