My research group is working on the development of new quantum devices, especially lasers, and their optimization for sensor systems and their applications in environment and health. Our special focus is currently on Quantum Cascade (QC) lasers, a novel type of semiconductor injection laser based on electronic intersubband transitions in the conduction band of a coupled quantum well heterostructure. Quantum wells are slivers of one type of semiconductor material, just a few atomic layers thick, interleaved with another type of semiconductor (the barriers).