Background
Quantum-well inter-subband devices, such as quantum-well infrared photo-detectors (QWIPs) and quantum cascade lasers (QCLs) are ideal for a variety of ground and space-based applications. Night vision, early warning systems, navigation, flight control systems, weather monitoring, security and surveillance are among the different applications based on QWIPs. QCLs are ideal candidates for the remote sensing of gases in the atmosphere.