Highly Efficient Ultraviolet Third‐Harmonic Generation in an Isolated Thin Si Meta‐Structure

Nonlinear nanophotonic devices have shown great potential for on-chip information processing, quantum source, 3D microfabrication, greatly promoting the developments of integrated optics, quantum science, nanoscience and technologies, etc. To promote the applications of nonlinear nanodevices, improving the nonlinear efficiency, expanding the spectra region of nonlinear response and reducing device thickness are three key issues. Herein, this study focuses on the nonlinear effect of third-harmonic generation (THG), and present a thin Si meta-sructure to improve the THG efficiency in the ultraviolet (UV) region. The measured THG efficiency is up to 10