Optical Beam Steering Using Tunable Metasurfaces

Optical beam steering is needed in many applications including, for example, LIDAR, optical communications, laser machining, and 3D printing. Autonomous cars and drones need LIDAR, the increasing demand for optical bandwidth shows no sign of abating, and advanced manufacturing using lasers continues to gain importance; such applications drive growing demand for optical beam steering devices and motivates research on new approaches and technologies. Tunable metasurfaces hold the promise of nonmechanical solid-state integrated beam steering devices, fabricated using wafer-scale processes amenable to mass manufacturing. Although still in its infancy, the field of tunable metasurfaces for optical beam steering is showing significant promise through an early demonstration of concepts, further motivating an already vigorous research effort globally. The purpose of this Perspective is to assess progress on optical beam steering using dynamically tunable nanoantennas and metasurfaces. Recent results are highlighted, and the state of the field is given a critical look.