Terahertz wave detection by plasmonic-antenna enhanced sum frequency generation

Abstract

We propose a scheme of terahertz (THz) indirect detection via plasmonic-antenna enhanced sum frequency generation process, where the THz wave is converted to optical wave that is detected by photodetector. The gold antenna built in the structure can improve the conversion efficiency by enhancing both the optical wave and THz wave. The numerical simulations show that the field enhancement is influenced by the geometry of the antenna, so the conversion efficiency can be improved highly by optimizing the antenna. Compared with commercial detectors, our detection system has a much lower noise equivalent power (NEP) of 15.4[Formula: see text]pW/[Formula: see text] at 5[Formula: see text]THz.