THz GaAs/AlGaAs Quantum Well Detector

We have designed and tested basic operation of a GaAs/AlGaAs quantum well photodetector in THz range of spectrum (3 THz, 100 mum). Responsivity of a few mA/W was measured, however achieving of the background-limited performance was not feasible because of high level of the dark current. Suitability of the device for practical applications will depend on further improvements of the design. We believe that better performance can be attained by optimizing the doping levels in the quantum wells. To evaluate suitability of the quantum well detectors for THz imaging, a small (up to 32 elements) prototype array will be tested.