We demonstrate a new waveguiding structure for terahertz (THz) radiation, in which broadband THz pulses are confined and guided along a bare metal wire. This waveguide exhibits close to the lowest attenuation of any waveguide for broadband THz pulses reported so far. It also supports propagation of broadband radiation with negligible group-velocity dispersion, making it especially suitable for use in pulsed terahertz sensing and diagnostic systems. In addition, the structural simplicity lends itself naturally to the facile manipulation of the guided pulses, including coupling, directing, and beam splitting. These results can be described in terms of a model developed by Sommerfeld, for waves propagating along the surface of a cylindrical conductor.
Wang, K., & Mittleman, D. M. (2007). Guided Propagation of Terahertz Pulses on Metal Wires. In Terahertz Frequency Detection and Identification of Materials and Objects (pp. 55–68). Springer Netherlands. https://doi.org/10.1007/978-1-4020-6503-3_5