Dispersion and transitions of dipolar plasmon modes in graded plasmonic waveguides

Abstract

Coupled plasmon modes are studied in graded plasmonic waveguides, which are periodic chains of metallic nanoparticles embedded in a host with gradually varying refractive indices. We identify three types of localized modes called "light", "heavy", and "light-heavy" plasmonic gradons outside the passband, according to various degrees of localization. We also demonstrate new transitions among extended and localized modes when the interparticle separation $d$ is smaller than a critical $d_c$, whereas the three types of localized modes occur for $d>d_c$, with no extended modes. The transitions can be explained with phase diagrams constructed for the lossless metallic systems.

arXiv commentPreliminary results have been presented at ETOPIM 7. Submitted to Appl. Phys. Lett

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Cited by in corpus (1)

• Tunable Localization and Oscillation of Coupled Plasmon Waves in Graded Plasmonic Chains