Nanofocusing of terahertz wave on conical metal wire waveguides

The nanofocusing of the terahertz (THz) radiation energy is studied. By using a conical metal nanowire waveguide, we focus the energy of the terahertz surface plasmon polaritons (THz SPPs) to several nanometers' scale. Another interesting property of the THz SPPs propagation on the waveguide is that the peak electric field at the waveguide tip enhances many times. What is more, both the phase velocity and the attenuation coefficient versus the wire radius are obtained. The terahertz energy nanofocusing opens the way to observe terahertz propagating and imaging on the nanoscale. (C) 2009 Elsevier B.V. All rights reserved.