Glossary
Quantum cascade lasers

semiconductor quantum well; puits quantique de semi-conducteur

Artificial material consisting of a semiconductor with a low bandgap energy, sandwiched between two semiconductor layers with the same lattice parameter and a higher bandgap energy.

intersubband transition; transition intersousbande

Transition between electronic states confined in a quantum well.

miniband (minigap); miniband (minigap)

Set of allowed (forbidden) electronic states in a set of tunnel-coupled quantum wells. Minibands and minigaps are used in the active region to define the regions in which electronic transport can take place.

cascade effect; cascade mechanism

Mechanism at the heart of quantum cascade laser operation: during laser operation, each electron injected into the active region produces one photon per period making up the active region.

distributed feedback laser