Detection and Homodyne Mixing of Terahertz Gas Laser Radiation by Submicron GaAs/AlGaAs FETs

We demonstrated detection and homodyne mixing of laser modes of optically pumped terahertz gas laser at 2.52 THz by submicron AlGaAs/GaAs field-effect transistors (FETs). The mechanism of the detection of terahertz radiation is based on the phenomena of non-linear excitations of plasma waves in a channel with 2D electron gas. According to theoretical models, the response time associated with this detection mechanism can be as fast as picoseconds, which makes these plasma wave devices attractive for real time detection and heterodyne mixing applications in the terahertz frequency range.