Solid-State Plasma Reconfigurable Terahertz Metasurface for Integrated Spatial-Amplitude–Phase–Frequency Modulation

The terahertz (THz) waves have broad application prospects in communication, imaging, detection, and other fields. Achieving arbitrary control of THz waves is key to advancing THz technology. Digital coding and programmable metasurfaces establish a connection between the physical world and information science, enabling a series of new information systems with novel architectures and mechanisms. This article proposes a high-integration solid-state plasma reconfigurable THz metasurface for integrated spatial-amplitude–phase–frequency modulation. This metasurface is designed based on lateral surface solid-state plasma devices, which generate or annihilate solid-state plasma regions by applying an external voltage. This design allows for not only dynamic and continuous control of the transmission amplitude (−117 to −0.01 dB) and reflection amplitude (−20.5 to −0.2 dB) but also achieves a linear variation of the unit reflection phase difference from 160° to 360° across multiple frequency bands. Furthermore, this article investigates a programmable metasurface composed of $36\times 36$ solid-state plasma units. By controlling the coding sequences of the digital metasurface, we demonstrate THz wavefront modulation and real-time reconfiguration of transmission–reflection across multiple frequency bands, validating the performance of the proposed metasurface.