Animated Ultraviolet Holography via Programmable Nonlinear Phase Transfer

Abstract

Dynamic and programmable control of ultraviolet (UV) light remains challenging because of conventional high material absorption and the limited functionality of optics such as lenses, mirrors or filters, and optoelectronic devices, such as spatial phase modulators, over the UV range. Here, by employing the concept of virtual metasurfaces based on arrays of programmable optical patterns on a 600-nm-thick lithium niobate film as the nonlinear medium, we demonstrate nonlinear phase transfer, generating programmable holography in the UV range. This arrangement provides a unique platform for generating animated holograms. A spatial light modulator encodes a computer-generated phase distribution onto a longer-wavelength pump beam, while second-harmonic generation transfers the programmed spatial phase to the UV field through the quadratic nonlinear interaction. Importantly, the nonlinear film serves as a simple frequency-conversion interface, eliminating the need for nanostructure patterning or direct UV spatial modulation. By incorporating the nonlinear phase relationship into the hologram design, we experimentally reconstruct six distinct UV holographic patterns, with normalised cross-correlation values ranging from 0.68 to 0.83, demonstrating reliable UV holographic image reconstruction. As a result, the dynamic updating of the SLM enables animated UV holograms at 10 Hz, demonstrating reconfigurable UV holography using the same nonlinear film. The system also supports tunable SHG emission from 350 to 390 nm and dynamic beam steering at approximately 20 Hz. The results demonstrate the potential of virtual metasurfaces to realise software-defined UV holography by transferring spatial programming across optical frequencies. This opens new opportunities for reconfigurable short-wavelength UV beam shaping and structured illumination, without the need for UV-compatible optics or optoelectronics.