Terahertz surface plasmon polaritons on a helically grooved wire

The propagation of tightly confined terahertz surface plasmon polaritons on a helically grooved metal wire has been studied both experimentally and theoretically. The periodic structure of such metawires allows the formation of surface electromagnetic modes with different azimuthal symmetry at wavelengths longer than the pitch. There is good agreement between the experimentally determined band edge frequencies of these modes and numerical calculations for the structure investigated. (C) 2008 American Institute of Physics.