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

The authors report on tunable terahertz resonant detection of two 1.55μm cw lasers beating by plasma waves in AlGaAs∕InGaAs∕InP high electron mobility transistor. The authors show that the fundamental plasma resonant frequency and its odd harmonics can be tuned with the applied gate voltage in the range of 75–490GHz. The observed frequency dependence on gate bias is found to be in good agreement with the theoretical plasma wave dispersion law.