Terahertz detection and imaging using an uncooled off-the-shelf GaN High Electron Mobility field-effect Transistor

In this paper, the capability of an uncooled commercially available GaN transistor for detection of terahertz radiation is reported. Detection measurements are performed for a range of applied gate voltages from −3 to 0 V in order to characterize the transistor response as a terahertz detector. The device is excited at 0.291 THz. Comparing experimental results with the theoretical ones, we show that the device works as a non-resonant terahertz detector at room temperature. The noise equivalent power (NEP) of the device amounts to 0.86nW/Hz
^0.5
at a gate bias voltage of −2.67V. The device is thereafter used as the detector of a terahertz imaging system. Its capability for inspection of hidden objects is demonstrated.