Fig. 2

Meta-optics for EFISHG. a Left: scanning electron microscopy (SEM) image of the plasmonic metasurface consists of Au hole array. Right: the dependence of the modulation depth on the applied DC voltage [71]. b Left: schematic image of the dielectric metasurface consists of silicon grating that supports Mie resonance. Right: the dependence of the modulation depth on the applied voltage under the excitation with the TM- (red) and TE- (black) polarized light [72]. c Top: schematic of EFISHG in an ITO/PFO/Al metafilm. Bottom: the dependence of the SHG intensity on the applied voltage [73]