3.8 mW terahertz radiation generation over a 5 THz radiation bandwidth through large area plasmonic photoconductive antennas

We present a high-performance terahertz radiation source based on a two dimensional array of plasmonic photoconductive antennas. Use of plasmonic antennas enhances photocarrier concentration near terahertz radiating elements and allows a faster acceleration of photocarriers. Therefore, a much stronger dipole moment is induced in response to an incident optical pump and significantly higher optical-to-terahertz conversion efficiencies are achieved compared to conventional designs. We experimentally demonstrate record-high terahertz radiation power levels as high as 3.8 mW over 0.1-5 THz in response to a 240 mW optical pump beam, exhibiting one order of magnitude higher optical-to-terahertz conversion efficiencies compared to conventional designs.