The optical response of carbon nanotubes

We have conducted reflectivity measurements on carbon nanotubes from the far-infrared up to the ultraviolet (from 20 cm−1 up to 3× 104 cm−1), in order to achieve the complete excitation spectrum. We have analysed our experimental findings in terms of the Maxwell-Garnett (MG) effective medium model, where small conducting particles are dispersed in a dielectric host-medium. We establish that carbon nanotubes have an intrinsic and anisotropic metallic behaviour.