Improved quantum cascade laser

摘要

A novel quantum cascade (QC) laser comprises a multiplicity of identical repeat units, with each repeat unit comprising an active region and an injector region. The injector region comprises quantum wells and barriers, selected to facilitate, under appropriate bias, resonant carrier transport from a lower energy level of a given active region to an upper energy level of an adjacent downstream active region. Carrier transition from the energy level to a lower energy level of an active region results in emission of infrared radiation. The laser is advangeously used in, e.g., a measurement system for detection of trace compounds in air. <IMAGE>