Boosted second-harmonic generation in the LiNbO${}_3$ metasurface governed by high-Q guided resonances and bound states in the continuum

Ze Zheng, Lei Xu, Lujun Huang +4

To date, second-harmonic generation (SHG) at nanoscale has been concentrated on employing high-refractive-index nanostructures, owing to the strong field confinement at deep subwav…