Printed Nb₂O₅ Metasurfaces for Ultraviolet-Visible Chiro-Optical Holography

The development of printable high-index materials that operate reliably across the UV-vis spectrum is critical for advancing large-area, high-performance metasurfaces. While the concept of particle-embedded resin (PER) enables single-step fabrication of high-index structures, most reported PERs exhibit limited transparency or refractive index in the UV region. In this study, a broadband chiral metahologram is reported enabled by a niobium pentoxide (Nb₂O₅) PER that exhibits a high refractive index and low absorption across 375-635 nm. The metasurfaces are fabricated in a single step using nanoimprint lithography, eliminating the need for etching or deposition. A particle swarm optimization (PSO) algorithm is employed to refine the geometric phase design for efficient polarization conversion. The resulting metasurfaces selectively reconstruct holographic images under left-circularly polarized (LCP) incidence, while suppressing those under right-circularly polarized (RCP) illumination. Experimental validation confirms high-fidelity reconstruction across the UV-vis range, accompanied by strong polarization-dependent holographic response governed by phase modulation. This work establishes a scalable platform for polarization-encoded photonics and suggests applications in optical security, biosensing, and spin-based information display.