Low-Crosstalk and Independent Amplitude/ Polarization Control in Near- and Far-Fields using a Dielectric Metasurface

Metasurfaces offer precise control over multidimensional light fields at subwavelength resolution, positioning them as powerful platforms for manipulating both near- and far-field optical distributions. Recent progress has concentrated on achieving simultaneous amplitude and polarization modulation in both fields using single-layer metasurfaces to increase information capacity. However, existing multiplexing techniques remain limited in enabling arbitrary, independent customization of amplitude and polarization characteristics across near- and far-fields within a single metasurface design. Here, a vectorial metasurface capable of fully decoupled near- and far-field multiplexing is presented, allowing independent control over amplitude and polarization in both spatial and spectral domains. By employing geometric-phase metasurfaces with four-nanopillar supercells, the generation of two distinct vectorial light fields with different amplitude and polarization distributions in the near- and far-field is experimentally demonstrated. This complete decoupling is achieved using a modified two-loop-iteration GS algorithm that simultaneously optimizes amplitudes and polarization profiles across both optical regimes. This approach establishes a new paradigm in multidimensional vector-field multiplexing, with applications spanning polarization-encoded encryption, complex vector beam generation, and high-density data storage.