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

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 (SiN_x), 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.