Low‐Crosstalk and Independent Amplitude/Polarization Control in Near‐ and Far‐Fields Using a Dielectric Metasurface

Abstract

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.