We used AlGaN/GaN high electron mobility transistors as room-temperature direct detectors of radiation at 0.15 THz from a free electron laser, hence 5 times higher than their cutoff frequency of 30 GHz. By near-field active mapping we investigated the antenna-like coupling of the radiation to the transistor channel. We formulate a model for the detection based on self-mixing in the transistor channel. The noise equivalent power is found in the range of 10-7 W/Hz0.5 without any optimization of the device responsivity. Present day AlGaN/GaN fabrication technology may provide operation at higher frequency, integration of amplifiers for improved responsivity and fast switches for multiplexing, which make the detector here described the basic element of a monolithic terahertz focal plane array.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
Ortolani, M., Di Gaspare, A., Giovine, E., Evangelisti, F., Foglietti, V., Doria, A., ... Cetronio, A. (2009). Imaging the coupling of terahertz radiation to a high electron mobility transistor in the near-field. Journal of the European Optical Society, 4, -. . https://doi.org/10.2971/jeos.2009.09006