High power pulsed terahertz radiation from large area plasmonic photoconductive emitters

We experimentally demonstrate a novel large area photoconductive emitter based on a two dimensional array of plasmonic contact electrode gratings to achieve better optical-to-terahertz conversion efficiencies compared to conventional designs. The use of plasmonic contact electrodes enhances the time-varying dipole moment induced within the device active area by offering a more efficient separation and acceleration of optically-generated carriers. Pulsed terahertz radiation powers as high as 3.8 mW over 0.1-5 THz frequency range are achieved at 240 mW optical pump power.