Field enhancement effect in nano-electrodes for THz generation and detection

Abstract

Recently, nano-structures have been adopted for the photonics-based THz emitters and detectors to enhance their output power and detection sensitivity. The notable improvements have been attributed to the plasmon enhanced absorption. However, we found that the field enhancement at the extremities of the nano-structure dominates over the plasmon effect, may be maximized by considering nano-scale ultrafast carrier dynamics. In this work, we present experimental results which support our conclusions. By understanding the underlying physical processes, we may derive an optimized device design for the emission and detection of continuous-wave and pulsed THz radiation.