We study the scattering and absorption of an H-polarized plane electromagnetic wave by a circular silver nanotube in the visible range of wavelengths using the separation of variables. The computed spectra of the extinction cross section display several hybrid localized surface-plasmon resonances of the dipole and multipole type. Analytical equations are derived for their resonance wavelengths. Bulk refractive-index sensitivities of nanotube-based sensors are determined, showing higher values for multipole resonances.
We studied the scattering and absorption of the H-polarized plane wave by a graphene-covered circular dielectric cylinder and a hollow tube with a graphene cover on the outer boundary in the terahertz range. The analytical solution of the wave-scattering problem was based on the Maxwell equations and the use of the separation of variables in the polar coordinates. We assumed the resistive boundary conditions on the zero-thickness graphene cover where the graphene electron conductivity was included as a parameter and was determined from the Kubo formalism. The computed spectra of the total scattering cross section and the absorption cross section displayed several types of resonances: the localized-surface-plasmon (LSP) resonances of the graphene cover and the resonances on the whispering-gallery modes of a dielectric cylinder or dielectric tube. The computed data can be useful for the design of graphene-based sensors of the changes in the refractive index of the host medium. For this purpose, the sensitivities and the figure-of-merit values of the LSP resonances were computed; their comparison demonstrated advantages of a thin-tube configuration.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.