Terahertz quantum-well photodetector

The design and projected performance of quantum-well infrared photodetectors (QWIP) for the terahertz (1-10 THz) or the very-far-infrared region are presented together with our initial demonstration of a GaAs/AlGaAs QWIP working at photon energies below the optical phonons. We point out the problem with this initial device, discuss possible causes, and suggest areas of improvement.