Nonlinear Metasurfaces: A New Paradigm for Short-Wavelength Generation and Modulation

Ultraviolet (UV) light has a shorter wavelength and higher photon energy, making it critical for numerous applications such as spectroscopy, microscopy, and information processing. Compared with conventional approaches, nonlinear metasurfaces offer a compact and flexible platform for UV light generation and manipulation. They leverage the strong light–matter interactions and resonant effects to efficiently convert fundamental light into the UV region. In this perspective, we reveal the underlying principles of UV generation based on nonlinear metasurfaces and review the latest advances in ultraviolet light generation and manipulation by plasmonic and dielectric nonlinear metasurfaces. Finally, we discuss the current challenges and future directions. We believe that nonlinear metasurfaces hold great potential for advancing UV photonics.