Semiconductor quantum well lasers with nanoscale resonant periodic active layers

Quantum dot semiconductor lasers have been the subject of significant investigation for many years. In part this is for potential applications based on desirable properties when compared with traditional quantum well-based lasers such as ultra-low threshold current density and reduced temperature sensitivity. The most common technique for quantum dot growth is the self-assembly technique, in which dots form as a result of the large strain which exists between the dot material and substrate material. Unfortunately self-assembly results in dots with random positions and a broad size distribution. This leads to inhomogeneous broadening, decreased peak gain, and increased threshold current density. The lack of complete control over individual quantum dot properties inherent with the self-assembly technique has been the predominant obstacle to realizing their full potential for use in photonic devices.