GaAs AlCaAs quantum cascade intersubband and interminiband emitter

The growth and characterization of quantum well structures based on the GaA s/AlGaAs material system is reported. Electroluminescence spectra from inte rsubband and interminiband transitions are shown. The quantum cascade struc tures are designed to emit mid-infrared radiation in the range from 7 to 12 mu m. Radiation from intersubband transitions in a coupled quantum well sy stem and interminiband transitions in undoped finite superlattices up to ro om temperature is reported. In finite superlattices emission from vertical transitions from different miniband states can be seen at low temperatures. (C) 1999 Elsevier Science B.V. All rights reserved.