Engineering the Propagation Properties of Planar Plasmonic Terahertz Waveguides

We recently demonstrated that periodically perforated metal films allow for the creation of complex planar plasmonic terahertz-guided-wave devices. Here, we experimentally examine the effect of changing the geometrical parameters of the periodic perforations on the propagation properties of these devices. These changes allow one to engineer the number of propagating modes and their corresponding frequencies, by varying the metal film thickness and the aperture dimensions, respectively, as well as the mode size and associated loss, by varying the aperture periodicity and width. Such information is of critical importance for optimizing the design parameters of these devices.