Increase in terahertz radiation power of plasmonic photoconductive antennas by embedding buried three-stepped rods in electrodes

In this work, a periodic structure with three-stepped metallic rods is designed for increasing terahertz (THz) radiation power of plasmonic photoconductive antennas (PCAs). Embedding this structure in electrodes of PCAs increases power of incident laser beam at 0.8 µm wavelength transmitted into the LT-GaAs substrate from 35% in a plasmonic PCA with rectangular rods to approximately 100%. Obtained analytical results in this study along with measurement results, reported in the literature, confirm that generated THz current of plasmonic PCA is increased up to 82% by using the buried three-stepped rods instead of rectangular rods. Consequently, THz radiation power is enhanced by 226%. Therefore THz radiation power of conventional plasmonic PCAs can be effectively enhanced by the designed buried three-stepped metallic rods.