title: Enhanced coupling of terahertz radiation to cylindrical wire waveguides.
abstract: Wire waveguides have recently been shown to be valuable for transporting pulsed terahertz radiation. This technique relies on the use of a scattering mechanism for input coupling. A radially polarized surface wave is excited when a linearly polarized terahertz pulse is focused on the gap between the wire waveguide and another metal structure. We calculate the input coupling efficiency using a simulation based on the Finite Element Method (FEM). Additional FEM results indicate that enhanced coupling efficiency can be achieved through the use of a radially symmetric photoconductive antenna. Experimental results confirm that such an antenna can generate terahertz radiation which couples to the radial waveguide mode with greatly improved efficiency.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Deibel
authors.forename: Kanglin
authors.initials: K
authors.lastname: Wang
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Escarra
authors.forename: Daniel
authors.initials: D
authors.lastname: Mittleman