Diatomic Metasurface for Vectorial Holography

TLDR

Emerging metasurfaces can arbitrarily manipulate wavefronts, reviving holography, but most metaholograms suffer from limited polarization control, narrow bandwidth, and complex, spatially variant designs. The study introduces a vectorial holography concept based on diatomic metasurfaces composed of orthogonal meta‑atoms. By arranging metamolecules of two orthogonal meta‑atoms, the design achieves a linear relationship between phase and polarization modulation through displacements and orientations of identical meta‑atoms. The method produces broadband vectorial holographic images with spatially varying polarization and dual‑way switching that are robust to incident angle and wavelength, offering a new route to achromatic diffractive elements, polarization optics, and ultrasecure anticounterfeiting.

Abstract

The emerging metasurfaces with the exceptional capability of manipulating an arbitrary wavefront have revived the holography with unprecedented prospects. However, most of the reported metaholograms suffer from limited polarization controls for a restrained bandwidth in addition to their complicated meta-atom designs with spatially variant dimensions. Here, we demonstrate a new concept of vectorial holography based on diatomic metasurfaces consisting of metamolecules formed by two orthogonal meta-atoms. On the basis of a simply linear relationship between phase and polarization modulations with displacements and orientations of identical meta-atoms, active diffraction of multiple polarization states and reconstruction of holographic images are simultaneously achieved, which is robust against both incident angles and wavelengths. Leveraging this appealing feature, broadband vectorial holographic images with spatially varying polarization states and dual-way polarization switching functionalities have been demonstrated, suggesting a new route to achromatic diffractive elements, polarization optics, and ultrasecure anticounterfeiting.