Terahertz detection sensitivity enhancement by using plasmonic contact electrode gratings

A novel photoconductive terahertz detector based on plasmonic contact electrode gratings is presented, which provides significantly higher detection sensitivities compared to conventional photoconductive terahertz detectors. Terahertz detection sensitivity enhancement is the result of reducing the average transport path of photo-generated carriers to the plasmonic contact electrodes, making it possible to generate higher output photocurrents under the same terahertz and pump power levels. We experimentally demonstrate a plasmonic photoconductive detector, which offers more than 30 times higher terahertz detection sensitivities compared to a comparable conventional photoconductive detector without plasmonic contact electrodes over 0.1-1.5 THz frequency range and under the same operation conditions.