Tunable Magnetic Fano Resonances on Au Nanosphere Dimer–Dielectric–Gold Film Sandwiched Structure

The Fano resonance demonstrates excellent performance due to its narrow asymmetrical spectral line shape, and sensitivity structure material parameter changes. Compared conventional resonances, the generated by magnetic dipole is more advantageous because of high absorption low loss. In this study, we propose an Au nanosphere dimer–dielectric–gold film sandwiched that supports mode. And can be efficiently tuned from visible near-infrared wavelength changing size gold nanospheres thickness dielectric layer. Different single nanosphere–dielectric–film structure, results suggest proposed sensitive polarization direction excitation light. Considering above characteristics, applied in multi-band sensing, surface-enhanced Raman spectroscopy, dynamically adjustable optical switches.