Ultra-Wideband Transmissive Metasurface With Independent Amplitude–Phase-Polarization Control for Co-Polarized Waves Empowered by Duplexing Meta-Particle

Artificially elaborated metasurfaces with unparalleled manipulation of electromagnetic (EM) waves have sparked revolutionary upsurge in the microwave, terahertz, and even optics fields. Whether as the basic dimensions of EM waves, or modulated degrees of freedom (DOFs) for metasurfaces, independent customization of amplitude, phase, and polarization plays crucial roles in endowing kaleidoscopic wavefronts. However, the existing methods for simultaneous control suffer from insufficient efficiency, limited bandwidth, and transformed polarization, especially for transmissive geometry. Enlightened by twisted nematic liquid crystals, a highly efficient ultra-wideband transmissive metasurface integrating duplexing meta-particles that can enable efficient tailoring of the above three profiles. The designed planar device with subwavelength thickness is not only to implement high-performance transmission (amplitude limitation of near-unity) for linearly polarized (LP) waves along bi-directions, but can achieve complete phase modulation in ultra-wide band (fractal bandwidth of 124%). Divertingly, dual-twisted structure further eliminates crosstalk, maintaining interactive function for designated co-polarization. The concept and significance of it are validated via two proof-of-prototypes demonstrating functionalities composed of cascaded metasurfaces, which generate 2-D airy beam and complex-amplitude meta-hologram. Thus, the proposed strategy constructs a robust platform for advanced wavefronts manipulation within ultra-wide band and high efficiency, and might have remarkable potentials in beam forming, duplex communications, and information encryption.