Hybrid Analytical-Numerical Analysis of Plasmonic Photoconductive Antennas

Photoconductive antennas (PCAs) have extensive technological applications as terahertz sources. Analysis of the performance of these antennas is typically challenging and time-consuming due to complicated interacting photonic and electromagnetic effects in the semiconductor material. The complexity even further increases in plasmonic PCAs because of the existence of periodic structures. In this paper, a numerical-analytical hybrid model is proposed for analysis plasmonic PCAs. Time-dependence and spatial-dependence of the electric field as well as carriers density generated in the semiconductor of plasmonic PCA, are calculated analytically and with finite element method, respectively. The presented model ultimately computes the current generated in the electrodes of plasmonic PCAs. Using this model, the performance of a typical plasmonic PCA as an example is investigated, and model results are validated by measurement results currently existing in the literature; though the model can also be used in the performance analysis of plasmonic PCAs with more complex periodic structures.