Beam-Reconfigurable Terahertz Metasurface with Optical Activations

Ultrafast reconfigurable devices with high-speed responses, high-resolution capabilities and ultra-compact sizes play important role in the real-time terahertz imaging, nondestructive detection, and low-latency communication systems. Reconfigurable terahertz metasurfaces as one of the reconfigurable devices, have enabled conspicuous functionalities of subwavelength planar devices and components for manipulating electromagnetic (EM) waves thanks to the ability at active and programmable controls. In this work, a coding metasurface integrating patterned phase change materials (PCMs), GeTe, is proposed. The proposed design benefits from the functionalities through different coding patterns and is capable of controlling beam tilting, directivity, and splitting of terahertz beams. The proposed concept was validated by feeding a metasurface with a wideband antenna while it can direct the main beam to 0° and 40° radiation with side lobe level of -15 dB.