Investigation of Fano resonances induced by higher order plasmon modes on a circular nano-disk with an elongated cavity
KAUST DepartmentPhysical Sciences and Engineering (PSE) Division
Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division
Electrical Engineering Program
Computational Electromagnetics Laboratory
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AbstractIn this paper, a planar metallic nanostructure design, which supports two distinct Fano resonances in its extinction cross-section spectrum under normally incident and linearly polarized electromagnetic field, is proposed. The proposed design involves a circular disk embedding an elongated cavity; shifting and rotating the cavity break the symmetry of the structure with respect to the incident field and induce higher order plasmon modes. As a result, Fano resonances are generated in the visible spectrum due to the destructive interference between the sub-radiant higher order modes and super-radiant the dipolar mode. The Fano resonances can be tuned by varying the cavity's width and the rotation angle. An RLC circuit, which is mathematically equivalent to a mass-spring oscillator, is proposed to model the optical response of the nanostructure design.
SponsorsThis work was supported in part by a Academic Excellence Alliance (AEA) program award from King Abdullah University of Science and Technology (KAUST) Global Collaborative Research (GCR) under the title "Energy Efficient Photonic and Spintronic Devices".