Shape of Fano resonance line spectra calculated for silver nanorods

Abstract

Using theoretical tools, we numerically demonstrated Fano line shapes in the scattering spectra of silver rods resulting from different mechanisms. One of the Fano line shapes is due to the coupling of an in-plane quadrupole and a dipole mode in a single rod. Two nodes were observed at the resonance wavelength, each of which is located at a quarter of the rod length from the two ends. The Fano resonance is strengthened when the silver rod is cut at the two nodal positions. The second mechanism that gives rise to a new Fano resonance peak occurs when the symmetry of the rod is broken and is a result of the asymmetric coupling between the two excited dipoles.

Fano resonance in novel plasmonic nanostructures

“…It has been evaluated that complex and hybrid structures can fulfill the FR requirement for bright and dark modes hybridization as well. For instance, a simple combination of a cross‐shaped structure and a nanobar can provide a clear evidence that once the energy of a dark mode approaches the energy of the bright mode, the FR can be observed as a characteristic asymmetric lineshape .…”

“…One important factor in the above‐mentioned studies is the scaling of nanostructures exhibiting FR . Most of the experimentally realized plasmonic structures have a characteristic scale of 100 nm and beyond . It has a deep physical reason based on the Mie theory, which has been discussed in less detail.…”

Fano-resonant metamaterials and their applications

“…In the structures with two elements (sometimes referred to as dimers [83,[85][86][87][88][89]) comprising the metamolecules, such as the ones shown in Figure 5A, the Fano resonance stems from the interaction between individual modes of these elements. Spectral repulsion between the modes necessitates that the frequencies of the hybrid bright and dark modes are mismatched.…”

Fano-like interference of plasmon resonances at a single rod-shaped nanoantenna

“…Interestingly, such a feature seems to go almost unnoticed for the nanoplasmonics community, despite being apparent in some previous references [2,7,15,17]. In fact, to the best of our knowledge, the only explicit report on the occurrence of Fano-like asymmetric line shapes in the scattering spectra of a single silver nanorod can be found in a recent paper by Reed et al [18], though the emphasis is put on dimer structures therein.…”