Experimental and numerical studies of terahertz surface waves on a thin metamaterial film

We present experimental and numerical studies of localized terahertz surface waves on a subwavelength-thick metamaterial film consisting of in-plane split-ring resonators. A simple and intuitive model is derived that describes the propagation of surface waves as guided modes in a waveguide filled with a Lorentz-like medium. The effective medium model allows to deduce the dispersion relation of the surface waves in excellent agreement with the numerical data obtained from 3-D full-wave calculations. Both the accuracy of the analytical model and the numerical calculations are confirmed by spectroscopic terahertz time domain measurements.