“…Supported by metal nanostructures in the sub-wavelength range, LSPR has a large local electromagnetic field enhancement effect [ 1 , 2 ], to be applied to surface-enhanced Raman scattering [ 3 , 4 ], electromagnetic induction transparency (EIT) [ 5 , 6 , 7 ], and in other fields. However, its quality factor (Q-factor) is relatively low (Q < 10) [ 8 , 9 ] to achieve ultra-narrow-band resonance due to the excessively high ohmic loss of the metal, thus resulting in the impracticality of potential applications based on surface plasmon resonance. In recent years, a large number of studies have extensively conducted and deeply explored the optical nanodevices that excite ultra-high Q resonance lines to overcome this defect, mainly focusing on: the resonators of high refractive index dielectric materials related to bound or quasi-bound states in the continuum excite the Fano resonance of high Q-factor through strong coupling between modes [ 10 , 11 , 12 , 13 , 14 , 15 ], and the plasma lattice resonance and Fano resonance based on periodic structure [ 8 , 16 , 17 , 18 , 19 , 20 , 21 ].…”