Investigation of Fano Resonances Induced by Higher Order Plasmon Modes on a Circular Nano-Disk With an Elongated Cavity

Abstract

Abstract-In this paper, a planar metallic nanostructure design, which supports two distinct Fano resonances in its extinction crosssection 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.

Twin Dipole Fano Resonances in Symmetric Three-Layered Plasmonic Nanocylinder

“…Oscillator |1〉 is driven by the time harmonic source V(t), which is analogous to the optical excitation of the superradiant bright mode. The subradiant dark modes are represented by oscillators |2〉 and |3〉, which will be excited only by coupling with oscillator |1〉 [16,23]. The coupled system of equations for the three oscillators |1〉, |2〉, and |3〉 arë…”

“…The optical response of MNC for α=90°having parameters 20/20, 30/30, and 45/45 nm is replicated using an electrical oscillator model that supports multiple resonances [16]. Here, the classical coupled oscillator system is described in terms of coupled RLC circuit as shown in Fig.…”

“…Recently, these resonances are studied in all types of plasmonic nanosystems due to the potential applications in metamaterials, surface-enhanced Raman spectroscopy (SERS), sensing, and slow-light devices [2][3][4][5][6][7]. These nanostructures include nanoshells [8][9][10][11], nanocones [12,13], ring/disk nanocavities [14][15][16], dimers [17][18][19], trimers [20], and nanoparticle aggregates [21,22], where the Fano resonance arises from the destructive interference of symmetric bright mode with the asymmetric dark plasmon mode.…”

Multiple higher-order Fano resonances in plasmonic hollow cylindrical nanodimer

“…He observed that destructive and constructive interferences take place due to the overlapping of a discrete state with a continuum state, which results in the asymmetric profile. Over the past few years, plasmonic nanosystems have been investigated for the generation of Fano resonances with sharp dispersion [2][3][4][5][6][7][8][9][10][11][12]. In such systems, Fano resonance arises due to the spectral overlapping of broad superradiant and narrow subradiant plasmon modes, which are usually characteristics of dipolar and higher-order plasmon modes, respectively.…”

Grating Effects on Sidelobe Suppression in Mim Plasmonic Filters

“…In [9] the use of metamaterials to construct a surface plasmon sensor with application at microwave frequencies was discussed. A planar metallic nano structure design was the research subject of [10]. The proposed structure could support two distinct Fano resonances in its extinction cross-section spectrum under normally incident and linearly polarized electromagnetic field.…”