Modeling terahertz plasmons in coupled semiconductor resonators

Plasmons in two-dimensional systems find applications in terahertz oscillators, detectors, filters, plasmonic crystals, etc. Numerous approaches to modeling plasmonic spectra exists, but little work has been done to compare results from theoretical calculations with each other, and so to understand their limitations. Using three different techniques (full-wave simulations, mode matching, and trasmission-line model), we analyse here a realistic structure comprising three coupled plasmonic resonators. While the results of all three models offer qualitatively similar results, revealing a rich spectrum of coupled modes, the values of the predicted resonant frequencies differ between the models. The best agreement is found between full-wave simulations and mode matching, both of which are based on rigorous solution of Maxwell's equations.