Terahertz (THz) metamaterials and transformation optics

Transformation Optics is a unique and novel technique for the design of complex electromagnetic materials with exotic and unprecedented properties. One of the most intriguing examples of a transformationoptical device was the experimental demonstration of an invisibility cloak. In this talk, the general methodology of transformation optics is introduced and discussed at the example of specific optical components like invisibility cloaks, electromagnetic concentrators, dynamic beam shifters and splitters, beam bends and waveguide bends. In a second part of the talk, we show how metamaterials can play an outstanding role as electromagnetic optical components for the THz technology. In contrast to a lack of the electromagnetic response of most natural materials to THz radiation, artificially composed metamaterials offer unique properties for the fabrication of functional, active electromagnetic components like THz modulators or other optical elements. Hereby, the constituents of the metamaterial allow an almost independent control of the permittivity and permeability tensors of the effective medium which can be exploited for the realization of media with negative refraction index. As examples, a bulk negative index material at THz frequencies and a polarization-independent THz modulator will be presented.