Polarization-customized holographic devices based on spin-decoupled plasmonic metasurfaces

Abstract

This invention relates to a polarization-customized holographic device based on a spin-decoupled plasmonic metasurface, belonging to the fields of micro-nano optics, diffraction optics, and holographic imaging. The device employs a three-layer metal-dielectric-metal reflective structure, consisting of a bottom metal reflective surface, an intermediate dielectric spacer layer, and a top anisotropic metaatomic layer. The top metaatomic layer is composed of various periodically arranged metaatoms. By superimposing the propagation phase and geometric phase, phase decoupling between left-handed circular polarization (LCP) and right-handed circular polarization (RCP) is achieved, allowing independent control of their phase delays. Precise customization of the output linear polarization direction is achieved by adjusting the phase difference between the two. This invention breaks the lock-in relationship between geometric phase and spin state in existing metasurface holographic devices, achieving highly integrated, high-quality polarization-customized holographic imaging. It exhibits stable performance over a wide spectral range and large incident angles, and can be widely applied in optical encryption, secure displays, and optical communications.

Images