Double Fano resonances due to interplay of electric and magnetic plasmon modes in planar plasmonic structure with high sensing sensitivity

Abstract

Double Fano resonant characteristics are investigated in planar plasmonic structure by embedding a metallic nanorod in symmetric U-shaped split ring resonators, which are caused by a strong interplay between a broad bright mode and narrow dark modes. The bright mode is resulted from the nanorod electric dipole resonance while the dark modes originate from the magnetic dipole induced by LC resonances. The overlapped dual Fano resonances can be decomposed to two separate ones by adjusting the coupling length between the nanorod and U-shaped split ring resonators. Fano resonances in the designed structure exhibit high refractive-index sensing sensitivity and figure of merit, which have potential applications in single or double-wavelength sensing in the near-infrared region.

Double fano resonances in a composite metamaterial possessing tripod plasmonic resonances

“…The first scheme is to employ one bright mode and two or more dark modes. Examples are abundant where a bright dipole couples with two dark dipoles or quadrupoles: one bright dipole resonator and a pair of split ring resonators (SRRs) as the dark elements [8], double symmetrical U-shaped SRRs with a nanorod between the two SRRs [9], plasmonic clusters of heptamer [10] and pentamer [11], and 3D metamaterials [12][13][14].…”

Double Fano resonances in nanoring cavity dimers: The effect of plasmon hybridization between dark subradiant modes

“…18 Multiple Fano resonances have also drawn a lot of attention because they can simultaneously modify the plasmon line at several spectral positions. [19][20][21][22][23][24][25][26][27][28][29] For example, double Fano resonances are investigated in coherent plasmonic cavities. 30 Multiple Fano resonances are very suitable for multi-wavelength biosensing, and FoM can be as large as 40 by using higher order Fano resonances.…”

Multiple Fano resonances in bimetallic layered nanostructures

“…The plasmonic Fano-like resonances exhibit sharp resonance and strong light confinement and are analogues of electromagnetically induced transparency (EIT) [1]. They have been observed in various symmetric and asymmetric metallic nanostructures that include nanoshells [2][3][4][5][6], multilayered nanocones [7], rings [8][9][10][11][12], dimers [13][14][15][16][17][18][19][20], trimers [21,22], quadrumer [23,24], pentamers [25,26], hexamer [27], and nanoparticle chains [28,29]. Among all the nanostructures, the plasmonic layered nanostructures have attracted many researchers attention because these structures exhibiting multiple Fano resonances over the entire visible spectrum as well as near to mid infrared region.…”