Nanostructured asymmetric dual-grating-gate plasmonic THz detectors: Enhancement of external coupling efficiency by array configuration and silicon-lens integration

摘要

We experimentally verify that the low external responsivity of nanostructured asymmetric-dual-grating-gate high-electron-mobility transistors (A-DGG HEMTs) as plasmonic terahertz detectors developed so far is attributed to their low external coupling efficiency. We separately demonstrate (1) 4-fold enhancement of the efficiency by an array of series-connected 4×1 detectors due to the increase in the effective active area and (2) 6-fold enhancement by the silicon-lens integration due to the better focusing inside the silicon lens. Those preliminary results indicate a possibility of enhancing external responsivities of A-DGG HEMTs up to their intrinsic values.