Tunable plasma wave resonant detection of optical beating in high electron mobility transistor

This paper presents the recent, experimental studies on the plasma resonant detection in high electron mobility transistors (HEMTs). Experiments were performed using an AlGaAs/lnGaAs/lnP HEMT with gate-length Lg = 800 nm. The whole HEMT structure is transparent to the incident radiation excepted the InGaAs-channel where the interband photoexcitation occurs. By using a tunable optical beating this photoexcitation is modulated over a large frequency range. Their mixing produces a tunable optical beating from 0 up to 600 GHz. The photoconductivity response, due to the difference frequency generation, is obtained by monitoring the modulation of the dc drain-to-source potential.