Coding metasurfaces can manipulate electromagnetic wave in real time with high degree of freedom, the fascinating properties of which enrich the metasurface design with a wide range of application prospects. However, most of the coding metasurfaces are designed based on external excitation framework with the wired electrical or wireless light control devices, thus inevitably causing the interference with electromagnetic wave transmission and increasing the complexity of the metasurface design. In this work, a simplistic framework of single-pixel-programmable metasurfaces integrated with a capsuled LED array is proposed to dynamically control electromagnetic wave. The framework fully embeds the photoresistor in the meta-atom, controlling the LED array to directly illuminate the photoresistor to modulate the phase response. With this manner, the complex biasing network is transformed to the universal LED array, which means the physical control framework can be transformed to a software framework, and thus the functions of the metasurface can be freely manipulated by encoding the capsuled LED array avoiding mutual coupling of adjacent meta-atoms in real time. All the results verify that the far-field scattering pattern can be customized with this single-pixel-programmable metasurface. Encouragingly, this work provides a universal framework for coding metasurface design, which lays the foundation for metasurface intelligent perception and adaptive modulation.
Read full abstract