Wide‐Angled Pragmatic Dielectric Chiral Meta‐Platform for Spin‐ and Wavelength‐Multiplexed Holography in the Ultraviolet and Visible

Abstract

A chiral meta‐optics platform that incorporates hologram‐multiplexing with low phase distortion and wide‐incident angle tolerance over the broad spectral range of the ultraviolet‐visible (UV–vis) regimes holds great potential for photonic‐encryption‐based applications, particularly in next‐generation 3D displays, high‐resolution biomedical imaging, holographic anti‐counterfeiting labeling, and multi‐channel optical communication. However, the design incorporating giant chirality from UV–vis wavelengths coupled with wide‐incident‐angle tolerance and cost‐effective fabrication is still challenging. Here, the study introduces a pragmatic multifunctional dielectric chiral meta‐platform designed for simultaneous spin‐ and wavelength‐multiplexing of optical information in the UV–vis spectrum. The unit cell comprises a dimer structure based on wide‐bandgap silicon nitride (SiNx), ensuring substantial dual‐spectrum chiro‐optical effects. The meticulously engineered chiral meta‐platform offers an incident angle tolerance of up to 40 degrees, coupled with significant chiro‐optical transmission. To demonstrate the concept, two distinct phase profiles are embedded in the meta‐platform, utilizing the spin and wavelength of incident light as keys to unlock the specific holographic information. The chiral meta‐platform is experimentally validated for oblique illumination angles, showcasing its adaptability across the UV–vis spectrum. The demonstrated meta‐device with dual‐spectrum visual encryption can be applied in various anti‐counterfeiting and security applications.