Abstract

At present, most terahertz (THz) technologies rely on free propagation rather than waveguide transportation. These systems have limitations such as large diffraction, and bulky volume, THz waveguides provide a promising approach to overcome these hurdles. Bare metal wires, which support a plasmonic mode, on their surfaces in THz range, are one of good candidates for THz waveguides with low loss and low dispersion [1]. Nevertheless, large mode mismatch between radially-polarized mode of a metal wire and linearly polarized mode in a free space hampers efficient coupling. Thus, coupling efficiency reported so far is lower than 0.5% [1, 2]. Attempts to increase the coupling efficiency of metal wire waveguides have been made, yet till now, to our knowledge, high-efficient coupling of broadband propagating THz wave to bare metal wires is not realized, and experimental investigations to determine coupling efficiency are not performed.

© 2013 IEEE