Omnidirectional absorption and off-resonance field enhancement in dielectric cylinders coated with graphene layers

Autor(es)

Arruda, Tiago Jose ^[1] ; Martinez, Alexandre Souto ^{[1, 2]} ; Pinheiro, Felipe A. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, BR-14040901 Sao Paulo - Brazil

^[2] Natl Inst Sci & Technol Complex Syst, BR-22290180 Rio De Janeiro - Brazil

^[3] Univ Fed Rio de Janeiro, Inst Fis, BR-21941972 Rio De Janeiro - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION; v. 32, n. 5, p. 943-948, MAY 2015.
• Citações Web of Science: 9

Resumo

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. (C) 2015 Optical Society of America (AU)

• Processo FAPESP: 10/10052-0 - Energia interna e espalhamento de ondas eletromagnéticas por esferas ou cilindros: ressonâncias de Fano e suas aplicações a metamateriais
• Beneficiário: Tiago José Arruda
• Modalidade de apoio: Bolsas no Brasil - Doutorado