Fano-like spectral profile in TE wave scattering by nanowire of dissipative and dispersive materials

Abstract

We report the result of extending the study of Fano phenomena in the scattering of TE electromagnetic wave by nanowire having complex and dispersive permittivities, [Formula: see text], on the basis of exact Mie formulation. It is shown that the spectral profiles of scattering coefficients are sensitively affected by imaginary part of the permittivity and its overall frequency dependent properties. The cascaded resonance profile reported previously for real and positive permittivity is suppressed by a large [Formula: see text] while the spectral profile is broadened by the dispersive nature of [Formula: see text] as to increase the asymmetry of the profile. The negative sign of the real part of the permittivity, except for [Formula: see text], is generally found to eliminate the resonace profile. Further, the size (radius) of the nanowire is also shown to affect the resonance profile. Specific scattering coefficients calculated for silicon (Si) and silver (Ag) nanowire using experimental data of corresponding [Formula: see text] are demonstrated to exhibit the spectral profile for certain wire sizes with nicely fitted Fano profile.