Magnetic-Based Fano Resonance by a Trimer with Y-shaped Gap
We introduce a Y-shaped gap into a silver disk to break the structure symmetry which can be looked as a loop-linked structure. Magnetic resonances are excited by incident light when incident electric field is parallel to the trimer plane. Fano resonance is generated by the coupling between bright electric mode and dark magnetic mode. These resonances can be adjusted by tuning the gap size, the radius of trimer, and the position of Y-shaped gap. The extinction cross section of the structure is calculated with the finite element method (FEM). The maximum figure of merit (FOM) is 37.8. Both the magnetic and electric field are greatly enhanced at the Fano dip and the magnetic resonance peak.
KeywordsFano resonance (FR) Magnetic resonance Figure of merit (FOM) Finite element method (FEM)
The work was supported by the Fundamental Research Funds for the Central Universities (GK201002038) and Natural Science Basis Research Plan in Shaanxi Province of China (2011JQ1014).
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