Metalens optical receiver for multi-beam free-space optical communication

A conventional optical receiver with a single detector accepts optical beams from a small range of angles of arrival (AoAs) and hence is not suitable for simultaneous communication with nodes with angular diversity. Here, we demonstrate a novel, to our knowledge, two-metalens-single-detector optical receiver that can collect optical beams coming from a wide range of AoAs. We show that the capability to collect broad AoAs with high efficiency makes the proposed receiver suitable for multi-beam free-space optical communication. An analysis for an exemplary three-beam system shows more than 70% collection efficiency at 2° AoA, which is 35× higher than conventional receivers.