Broadband Photoconductive Terahertz Detection with a 100dB Dynamic Range without Using a Short-Carrier-Lifetime Substrate
We present a photoconductive terahertz detector, which offers high-responsivity and broadband operation without using a short-carrier-lifetime substrate, for the first time. To achieve this unprecedented performance, we utilize a plasmonic nanocavity to confine the majority of optical pump photons in a thin photoconductive active region to maintain a sub-picosecond transport time for the majority of photocarrier to the device contact electrodes. Therefore, an ultrafast operation is achieved without using a short-carrier-lifetime semiconductor. We demonstrate terahertz detection with dynamic ranges exceeding 100 dB over a 0.1–4.5 THz frequency range.