Absorption and scattering properties of gold nanotubes with an offset core

Abstract:

The effects of core offset, dielectric constants of core and embedding medium as well as incident light direction on the absorption and scattering properties of gold nanotubes with a nonconcentric core are theoretically studied by the finite difference time domain method. The numerical results show that the absorption and scattering spetra red shift and the absorption-scattering ratio increases with increasing core offset distant of the inner core from the nanotube centre. Moreover, the absorption-scattering ratio also increases with the increased core dielectric constant or the decreased dielectric constant of embedding medium. When the incident light direction is parallel to core offset direction, the greater absorption-scattering ratio appears as the position of the core is close to the incident light, but the ratio is smaller than that one when the incident light direction is perpendicular to offset direction as the core offest is given.