Plasmon Resonances of a Square Silver Plate with a Symmetrically Inserted Glass Nanofiber

Abstract

A 2D problem of diffraction of a plane TM electromagnetic wave by a shell consisting of a square silver plate with a glass nanofiber inserted into it has been considered. In the wavelength range 330 nm < λ < 900 nm, spectra of the scattering cross section have been calculated using rigorous numerical methods. The effects of the silver loss and the angle of incidence of the plane wave on the scattering cross section and the scattering pattern has been investigated. It is shown that the presence of an insert in the form of a glass fiber results in a significant (of an order of 200 nm) shift of the dipole resonance into the optical region and, at the same time, in splitting and insignificant shift of the quadrupole resonances. It has been found that the maxima of the scattering pattern in the split nondegenerate resonances are displaced relative to each other by an angle of π/4.