Quantenkaskadenlaser

WO2003023909 A UPAB: 20030516 NOVELTY - Unipolar quantum cascade laser comprises a number of adjacent semiconductor multiple layer structures (3) arranged in a periodic sequence and through which an electron flow can be applied by providing contact points. A blocking layer (4) is provided within the semiconductor multiple layer structures and has an uppermost conduction band edge potential that is higher than the uppermost band edge potential of all the other semiconductor layers in the structure. DETAILED DESCRIPTION - Preferred Features: The blocking layer is arranged within the optically active region in the electron transporting direction directly next to the transition region (2). The blocking layer has a thickness of 1 nm or less. The semiconductor multiple layer structure is made from a semiconductor material system of a GaInAs/AlInAs or InGaAs/AlAsSb layer combination each fitted to a InP substrate. USE - Used as a unipolar quantum cascade laser. ADVANTAGE - Electron losses are avoided