Electrically controlled reconfigurable apertures for free space optical communications

Chip-scale beam steering units, which would replace currently used mechanical gimbals, could revolutionize the field of free space optical communications. We review chip-scale technologies, which enable electronic beam reconfigurations and steering without mechanically moving parts. We assess the feasibility of using different electrically steerable apertures such as active metasurfaces and optical phased arrays for laser communications. Our optical link budget analysis shows that, for metasurface apertures of 1 cm in diameter and input powers of 5 W, the free space link range can approach ~ 10,000 km. We also provide an outlook how the link range can be increased further.