Practical Metal-Wire THz Waveguides
  Several practical implementations of the THz wire waveguides are proposed combining the low-loss, low group velocity dispersion and simplicity of excitation of the two-wire metal waveguide with the ease of manufacturing, possibility of bending and a convenient access to a modal power of the hollow core waveguide. Optical properties of the wire waveguides are investigated experimentally by THz-TDS spectroscopy and numerically using the finite element method confirming TEM-mode guidance in a broad spectral range. 
Andrey Markov, Stephan Gorgutsa, Hang Qu and Maksim Skorobogatiy
physics.optics