Floating dielectric slab optical interconnection between metal-dielectric interface surface plasmon polariton waveguides

Au@Ag Core-Shell Nanorods Support Plasmonic Fano Resonances

In this work, we investigated experimentally and theoretically the plasmonic Fano resonances (FRs) exhibited by core-shell nanorods composed of a gold core and a silver shell (Au@Ag NRs). The colloidal synthesis of these Au@Ag NRs produces nanostructures with rich plasmonic features, of which two different FRs are particularly interesting. The FR with spectral location at higher energies (3.7 eV) originates from the interaction between a plasmonic mode of the nanoparticle and the interband transitions of Au. In contrast, the tunable FR at lower energies (2.92-2.75 eV) is ascribed to the interaction between the dominant transversal LSPR mode of the Ag shell and the transversal plasmon mode of the Au@Ag nanostructure. The unique symmetrical morphology and FRs of these Au@Ag NRs make them promising candidates for plasmonic sensors and metamaterials components.

Highly efficient plasmonic interconnector based on the asymmetric junction between metal-dielectric-metal and dielectric slab waveguides

A novel interconnection structure that is capable of transferring surface plasmon energy between two distanced metal-dielectric-metal waveguides is proposed. A numerical analysis indicates that the power transferring efficiency of the proposed structure approaches 88.5% for one millimeter of interconnection length. The main mechanism of the proposed interconnector is governed by Fabry-Pérot resonance and a multi-mode interference effect in the junction layers. A physical analysis based on the mechanism for designing an optimized structure is also provided, which could be used to modify the proposed structure.

Substrate-induced Fano resonances of a plasmonic nanocube: a route to increased-sensitivity localized surface plasmon resonance sensors revealed

Symmetry-breaking introduced by an adjacent semi-infinite dielectric can introduce coupling and hybridization of the plasmon modes of a metallic nanostructure. This effect is particularly large for entities with a large contact area adjacent to the dielectric. For a nanocube, a nearby dielectric mediates an interaction between bright dipolar and dark quadrupolar modes, resulting in bonding and antibonding hybridized modes. The Fano resonance that dominates the scattering spectrum arises from the interference of these modes. This analysis provides a strategy for optimizing the sensitivity of nanostructures, whether chemically synthesized or grown by deposition methods, as high-performance localized surface plasmon resonance sensors.