Abstract-Handbook of Terahertz Technology for Imaging, Sensing and Communications

W. Knap, M.I. Dyakonov,

https://www.sciencedirect.com/science/article/pii/B9780857092359500057

This chapter gives an overview of the main physical ideas and experimental results concerning the application of field effect transistors (FETs) for the generation and detection of terahertz (THz) radiation. Resonant frequencies of the two-dimensional plasma oscillations in FETs increase with the reduction of the channel dimensions and for submicron gate length reach the THz range. When the mobility is high enough, the dynamics of a short channel FET at THz frequencies is dominated by plasma waves. This may result, on the one hand, in a direct current (dc) induced spontaneous generation of plasma waves and THZ emission and, on the other hand, in a resonant photoresponse to incoming radiation. In other cases, when plasma oscillations are overdamped, the FET can operate as an efficient broadband THz detector.