A High-Sensitivity Terahertz Detector Based on a Low-Barrier Schottky Diode

A low-barrier Schottky barrier diode based on the InGaAs/InP material system is designed and fabricated with a new non-destructive dry over-etching process. By using this diode, a high-sensitivity waveguide detector is proposed. The measured maximum responsivity is over 2000 mV/mW at 630 GHz. The measured noise effective power (NEP) is less than 35 pW/Hz^0.5 at 570–630 GHz. The minimum NEP is 14 pW/Hz^0.5 at 630 GHz. The proposed high-sensitivity waveguide detector has the characteristics of simple structure, compact size, low cost and high performance, and can be used in a variety of applications such as imaging, molecular spectroscopy and atmospheric remote sensing.