Low‐noise heterodyne detection of terahertz waves at room temperature using zero‐biased Fermi‐level managed barrier diode

A Fermi‐level managed barrier (FMB) diode was used for the heterodyne detection of terahertz waves for the first time. A quasi‐optical module integrating an FMB diode and a broadband trans‐impedance amplifier exhibited an intermediate frequency bandwidth of 11 GHz. A very low noise‐equivalent‐power of 1.1 × 10 −18 W/Hz was achieved at ∼300 GHz with a very low local oscillator power of 6 × 10 −6 W.