Аннотация:In this work, we present the first experimental observation of the enhanced THz radiation in plasmonic photoconductive antenna (PCA) based on Bi2−xSbxSeyTe3-y topological insulator (TI). By using numerical simulations, we optimized the plasmonic grating geometry to maximize optical light transmission, stimulating efficient surface plasmon-polariton (SPP) excitations along the TI/grating interface. We fabricated two equal PCAs, the one of which contains high-aspect ratio plasmonic grating. The THz spectral measurements showed a ∼9-fold enhancement of the emitted THz power in the plasmonic TI-based PCA. The results of our study can open a pathway toward time-domain plasmonics-enhanced THz setups utilizing innovative photoconductive materials.