Active Anisotropic Coding Metasurface with Independent Real-Time Reconfigurability for Dual Polarized Waves

Active metasurfaces incorporated with active elements can achieve tunable and/or reconfigurable functionalities controlled by external stimuli, providing a new platform that may radically change the way people dynamically manipulate electromagnetic waves. Despite the rapid growth, most of the active metasurfaces so far are polarization-sensitive structures that only support tunable responses for excitation with a certain single polarization. Here, an ultrathin active anisotropic metasurface loaded with voltage-controlled varactors is reported to enable independent dual-polarization wavefront control. In particular, multichannel voltage output hardware system is used to realize 1-bit and 2-bit active coding metasurface with real-time reconfigurability independent for two linear-polarization channels. As the design examples, it is experimentally demonstrated that the far-field scattering behaviors of the metasurface for orthogonal two polarizations can be dynamically and independently tuned with totally distinct functionalities by simultaneously encoding dual-channel spatial coding sequences. The proposed concept of active anisotropy has largely enhanced the information capacity of the metasurface, bringing new degrees of freedom in achieving versatile tunable functionalities and offering untapped potentials for sophisticated electromagnetic wave manipulation such as dynamical signal processing, holography, arbitrary beam shaping, etc.