Low-loss terahertz transmission through curved metallic slit waveguides fabricated by spark erosion

Abstract

Propagation characteristics of broadband terahertz pulses in straight and curved metallic slit (MS) waveguides fabricated using spark erosion technique are investigated in the 0.1–1.0THz frequency range. As the straight MS waveguides, the curved MS waveguides, having radii of curvature as small as 5mm, exhibit comparably undistorted terahertz pulse transmission. The observed bending loss is unexpectedly low, giving rise to the assumption that surface oxidization and roughness generated by the fabrication process are responsible for the improved signal routing behavior. Experimental results are compared with theoretical data from numerical field simulations incorporating the influence of a thin dielectric cover layer.