A dual-pass high current density resonant tunnelling diode terahertz emitter

We report on a dual-pass high current density InGaAs/AlAs/InP resonant tunnelling diode (RTD) terahertz (THz) emitter. Our dual-pass technique reduces overall fabrication complexity, improves the reproducibility for creating low resistance ohmic contacts, and allows accurate control over the final device area. This has been made possible by measuring the RTD current-voltage (I-V) characteristic during the fabrication process and defining both contact electrodes at the start of the fabrication. We extract information about the RTD performance using this method and demonstrate fundamental room temperature emission at 0.35 THz.