Emission of terahertz radiation from dual grating gate plasmon-resonant emittersfabricated with InGaP/InGaAs/GaAs material systems

Abstract

This paper reviews recent advances in our original 2D-plasmon-resonant terahertz emitters.The structure is based on a high-electron-mobility transistor and featured with doublyinterdigitated grating gates. The dual grating gates can alternately modulate the 2Delectron densities to periodically distribute the plasmonic cavities along the channel, actingas an antenna. The device can emit broadband terahertz radiation even at roomtemperature from self-oscillating 2D plasmons under the DC-biased conditions. When thedevice is subjected to laser illumination, photo-generated carriers stimulate the plasmaoscillation, resulting in enhancement of the emission. The first sample was fabricated withstandard GaAs-based heterostructure material systems, achieving room temperatureterahertz emission. The second sample was fabricated in a double-decked HEMT structurein which the grating gate metal layer was replaced with the semiconducting upper-deck 2Delectron layer, resulting in enhancement of emission by one order of magnitude.