Design techniques for terahertz plasmonic filters

Wireless communication systems in the terahertz (THz) frequency range promise to dramatically increase available bandwidth in the electromagnetic spectrum. These wireless systems will require filtering techniques capable of operating in this relatively unused part of the spectrum. In pushing towards more advanced filtering techniques, we demonstrate a terahertz filter design methodology based upon k-space that shows more complex filters such as band-pass, comb-pass and polarization-dependent filters. Using this design flow, we demonstrate: setting the center frequency and bandwidth in THz band-pass filters, controlling the individual magnitudes of each resonant peak in a comb filter, adjusting the transmittance of a filter at two different frequencies by spatially rotating the filter, and varying the transmittance at a single frequency by changing the polarization angle of incoming radiation. We believe this new k-space filter design methodology will help to create more complex filters that will find application in wireless THz communication systems.