Abstract: Intersubband semiconductor lasers (ISLs) are of great interest for mid-infrared (2-20 ?m) device applications. These semiconductor devices have a wide range of applications from pollution detection and industrial monitoring to military functions. ISLs have generally encountered several problems which include slow intrawell intersubband relaxation times due to the large momentum transfer and small wave-function overlap of the initial and final electron states in interwell transitions. Overall, the ISL's of the prior art are subject to weak intersubband population inversion. The semiconductor device of the present invention provides optimal intersubband population inversion by providing a double quantum well active region in the semiconductor device. This region allows for small momentum transfer in the intersubband electron-phonon resonance with the substantial wave-function overlap characteristic of the intersubband scattering.

Abstract: A semiconductor light source is disclosed comprising a substrate, lower and upper claddings, a waveguide region with imbedded active area, and electrical contacts to provide voltage necessary for the wavelength tuning. The active region includes single or several heterojunction periods sandwiched between charge accumulation layers. Each of the active region periods comprises higher and lower affinity semiconductor layers with type-II band alignment. The charge carrier accumulation in the charge accumulation layers results in electric field build-up and leads to the formation of generally triangular electron and hole potential wells in the higher and lower affinity layers. Nonequillibrium carriers can be created in the active region by means of electrical injection or optical pumping. Radiative recombination occurs between the electrons and holes, accumulated in the ground states of the triangular potential wells formed in the high- and low-affinity layers of each active region periods.

Abstract: Intersubband semiconductor lasers (ISLs) are of great interest for mid-infrared (2-20 ?m) device applications. These semiconductor devices have a wide range of applications from pollution detection and industrial monitoring to military functions. ISLs have generally encountered several problems which include slow intrawell intersubband relaxation times due to the large momentum transfer and small wave-function overlap of the initial and final electron states in interwell transitions. Overall, the ISL's of the prior art are subject to weak intersubband population inversion. The semiconductor device of the present invention provides optimal intersubband population inversion by providing a double quantum well active region in the semiconductor device. This region allows for small momentum transfer in the intersubband electron-phonon resonance with the substantial wave-function overlap characteristic of the intersubband scattering.

Abstract: Intersubband semiconductor lasers (ISLs) are of great interest for mid-infrared (2-20 &mgr;m) device applications. These semiconductor devices have a wide range of applications from pollution detection and industrial monitoring to military functions. ISLs have generally encountered several problems which include slow intrawell intersubband relaxation times due to the large momentum transfer and small wave-function overlap of the initial and final electron states in interwell transitions. Overall, the ISL's of the prior art are subject to weak intersubband population inversion. The semiconductor device of the present invention provides optimal intersubband population inversion by providing a double quantum well active region in the semiconductor device. This region allows for small momentum transfer in the intersubband electron-phonon resonance with the substantial wave-function overlap characteristic of the intersubband scattering.