Terahertz and infrared transmission properties of super-thin periodic multi-walled carbon nanotube gratings

Abstract

Super-aligned multi-walled carbon nanotube arrays on Si wafer were synthesized by low press chemical vapor deposition. The super-thin multi-walled carbon nanotube films were obtained by a drawing process on the side of the vertically aligned carbon nanotubes. The as-synthesized samples were characterized by scanning electron microscopy and optical microscopy. Terahertz time-domain measurements showed that anisotropic transmission properties were observed. The multi-walled carbon nanotube films with various two-dimensional periods and thicknesses displayed remarkably enhanced transmission at the terahertz range. Comparing experimental results with theoretical calculations revealed that the excitation of surface plasmon polaritons on the carbon nanotubes/Si interface was the key mechanism responsible for the enhanced transmission. The resonance peaks were red shifted with increasing period. In the infrared region, no obvious resonance peaks were observed.