Stimulated emission from ultrathin InAs/GaAs quantum well heterostructures grown by atomic layer epitaxy

Abstract
We report the first observation of stimulated emission (16 K) in material grown by atomic layer epitaxy (ALE). The active region of our laser structure consists of six strained InAs quantum wells (6.6 Å thick, 7.4% strain) separated by 500 Å of GaAs, which makes these the thinnest and most highly strained quantum wells ever reported to support stimulated emission. These results demonstrate that the ALE process can be used to grow laser quality material with highly reproducible layer thickness.