Polarization-selective metasurfaces for dual-band multidimensional modulation

Abstract To meet the urgent demand for multidimensional modulation of dual-band multi-wavelength and polarization states in modern integrated optical systems, this paper proposes a dual-band multifunctional Pancharatnam–Berry phase metasurface platform based on spatial multiplexing and polarization selection. Four types of unit structure with distinct geometric parameters were designed to respond to right-circularly polarized (RCP) light at 532 nm and 660 nm, and left-circularly polarized (LCP) light at 1310 nm and 1550 nm, respectively, thereby achieving multidimensional modulation of phase and polarization across multiple wavelength channels in the visible and near-infrared dual-band. Based on this platform, three metasurfaces were designed and successfully demonstrated the following functions: (1) polarization-dependent dual-band discrete wavelength achromatic focusing; (2) polarization-dependent dual-band multi-wavelength super-dispersion focusing; (3) polarization-switchable dual-mode multifoci, where RCP encodes only phase information, while LCP employs complex amplitude modulation. This work effectively improves the limitations of traditional devices in wavelength band and modulation dimensions on a single ultra-thin platform. Its lightweight and high integration characteristics provide a promising solution for scenarios such as information multiplexing, biomedical imaging and optical communication.