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

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 sigma(cn)(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 sigma(cn)(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.