  Tunable nonlinearity facilitates the creation of reconfigurable nonlinear
metasurfaces, enabling innovative applications in signal processing, light
switching, and sensing. This paper presents a novel approach to electrically
modulate SHG from a lithium niobate (LN) metasurface, exploiting the
electro-optical (EO) effect. By fabricating a nanohole array metasurface on a
thin LN film and applying an electric field, we demonstrate the alteration of
the material's refractive index, resulting in resonance shifts and modulation
of SHG intensity at specific wavelengths. Our findings provide valuable
insights for the development of electrically tunable nonlinear light sources,
quantum optics, dynamic nonlinear holography, and nonlinear information
processing.
