Omnidirectional absorption and off-resonance field enhancement in dielectric cylinders coated with graphene layers
| Autor: | Tiago J. Arruda, Felipe A. Pinheiro, Alexandre Souto Martinez |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Materials science
business.industry Terahertz radiation Graphene Surface plasmon Physics::Optics Fano resonance Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials law.invention Optics law Computer Vision and Pattern Recognition ABSORÇÃO Surface plasmon resonance business Absorption (electromagnetic radiation) Plasmon Localized surface plasmon |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| ISSN: | 1520-8532 |
| Popis: | We investigate electromagnetic scattering and absorption by dielectric cylinders coated with a concentric plasmonic shell at arbitrary incidence angles. Exploiting bulk and surface plasmon resonances in the long wavelength regime, we obtain an analytical condition to achieve wide-angle enhanced absorption for both TE and TM polarizations. By using the Lorenz-Mie theory, we apply this result to investigate electromagnetic absorption in a silicon cylinder coated with a graphene monolayer epitaxially grown on silicon carbide. Our theoretical results show that enhanced absorption occurs for a broad frequency range in the terahertz, and that omnidirectional absorption exists at a frequency in between the bulk and localized surface plasmon resonances. By showing that omnidirectional absorption does not correspond to an extinction resonance, we associate this phenomenon with off-resonance field enhancement in this system, which in turn is explained in terms of Fano resonances in the graphene layer. |
| Databáze: | OpenAIRE |
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