Plasmonic terahertz monochromatic coherent emission from an asymmetric chirped dual-grating-gate InP-HEMT with a photonic vertical cavity

We demonstrate an intense stimulated emission of 0.1-1-μW terahertz (THz) monochromatic radiation in InP-based asymmetric chirped dual-grating-gate (AC-DGG) high electron mobility transistors (HEMTs) at 140-290K. In the research of modern THz electronics, development of compact, tunable and coherent sources operating in the THz regime is one of the hottest issues. Hydrodynamic nonlinearities of two-dimensional (2D) plasmons in HEMTs are promising for intense emission of THz radiation [1, 2]. Thanks to the dc-current-driven plasmon instabilities of the Dyakonov-Shur (D-S) type driven by a non-reciprocal Doppler effect in 2D electron channel with asymmetric boundary conditions [1] and/or the Ryzhii-Satou-Shur (R-S-S) type driven by electron-transit-time mechanism in a periodic structure [3] the gate-voltage tunable THz emission has been observed from GaN-, GaAs- and InP-based single-gate or symmetric dual-grating-gate (DGG) HEMTs [4-6].