Single-quantum-well grating-gated terahertz plasmon detectors

A grating-gated field-effect transistor fabricated from a single-quantum well in a high-mobility GaAs-AlGaAs heterostructure is shown to function as a continuously electrically tunable photodetector of terahertz radiation via excitation of resonant plasmon modes in the well. Different harmonics of the plasmon wave vector are mapped, showing different branches of the dispersion relation. As a function of temperature, the resonant response magnitude peaks at around 30 K. Both photovoltaic and photoconductive responses have been observed under different incident power and bias conditions. (C) 2005 American Institute of Physics.