Intersubband quantum box semiconductor laser

An intersubband quantum box laser structure includes an active structure having a two dimensional array of quantum boxes separated from one another in a semiconductor matrix. The quantum boxes are formed to suppress phonon-assisted transitions, and thus the transitions become primarily of the radiative type. Each quantum box has a multilayer structure including an electron injector, an active region with a quantum well, and an electron mirror. Electrons injected from the injector into the active region at a high energy level relax to a lower energy level with the emission of a photon at, for example, mid-infrared wavelengths. The mirror reflects electrons at the higher energy level at which they were injected and transmits electrons at the lower energy level after emission of a photon. Multiple layers of semiconductor are formed on each side of the active structure to provide conduction across the multiple layer structure and to provide optical confinement of the photons emitted. The semiconductor laser structure may be formed using various material systems, including InGaAs/InGaAsP structures grown on GaAs and InGaAs/AlInAs structures grown on InP.