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

Frontiers in Physics

Fang Guan¹  Wen Huang¹  Zhenjiang Wei¹  Tianxun Gong¹  Xiaosheng Zhang² 

[1] State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Electronic Science and Engineering (National Exemplary School of Microelectronics), University of Electronic Science and Technology of China, Chengdu, China;null;

关键词: Fano resonance;    magnetic mode;    surface plasmons;    Au nanosphere dimer-dielectric-gold film;    radiation loss;   

DOI  :  10.3389/fphy.2021.691027

来源: Frontiers

【 摘 要 】

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

【 授权许可】

CC BY