Optical scattering from a planar array of finite-length metallic carbon nanotubes

Abstract

A model is developed for optical scattering from planar arrays of finite-length single-wall metallic carbon nanotubes. The scattered field is predicted using a periodic Green's function for the array, which includes all electromagnetic interactions, and a quantum conductance function ${\ensuremath{\sigma}}_{\mathit{cn}}(\ensuremath{\omega})$ for the carbon nanotubes. It is found that for both individual carbon nanotubes and nanotube arrays, the optical far scattered field is proportional to ${\ensuremath{\sigma}}_{\mathit{cn}}(\ensuremath{\omega})$, so that scattering characteristics are governed by effects associated with electronic transitions. This is in strong distinction to the case for far-infrared arrays, where mutual electromagnetic coupling effects were previously found to be very important for a wide range of broadside nanotube spacings. Furthermore, due to strong damping, single-wall nanotubes do not exhibit longitudinal current resonances (optical antenna effects) associated with the finite length of the tubes, which is also quite different from the far-infrared result.