Strain compensated Si/SiGe quantum cascade emitters grown on SiGe pseudosubstrates

Abstract

Quantum cascade lasers (QCLs) based on III-V materials such as InGaAs/InAlAs [1] or GaAs/AlGaAs [2] have attracted an increasing attention since the first experimental demonstration in 1994. These convenient emitters have been successfully operated in the 3.4-24 μm range, and also recently in the terahertz range [3]. The concept of QCLs can also be applied to indirect bandgap materials since it relies on intersubband optical transitions for which the nature of the bandgap does not play any role. The Si/SiGe material system is particularly a candidate of interest, because of the possible compatibility with the well established Si integrated circuit processing.