THz Emission in a Dual-Grating-Gate HEMT Promoted by the Plasmonic Boom Instability

We experimentally observed photomixed THz emission from a dual-grating-gate high-electron-mobility transistor under different bias conditions at 120 K with irradiating photomixed dual-CW-IR laser beams. The observed emission spectral peak frequencies meet well to the theoretical calculations for plasmon mode frequencies, suggesting the photomixed THz emission is amplified by the DC-current-driven plasmonic boom type instability when the electron drift velocity exceeds the plasmon velocity at the plasmon cavity boundary.