Artificial Dielectric Beam-Scanning Prism for the THz Region

We design and fabricate an artificial dielectric prism that can steer a THz beam in space and experimentally investigate its behavior. The artificial dielectric medium consists of a uniformly-spaced stack of metal plates. At an operating frequency of 0.3 THz, we observe a maximum beam deflection of 29 degrees, limited by the precision of the available spacers. The very good agreement between the experimental deflection angle and the theoretical prediction strongly indicates the feasibility to practically realize much larger angles. In addition to the obvious practical application, at the fundamental level, this work also demonstrates the feasibility to realize zero-index materials.