Engineering quantum-dot lasers

We discuss recent progress in the engineering of quantum-dot (QD) lasers, focusing on the spectral output, dynamics and techniques for integration. Two approaches to such engineering are discussed. Firstly, it is suggested that control of lasing spectra in QD lasers is possible by making use of waveguiding-related phenomena (substrate leakage and reflection) which, in unoptimised laser structures, result in the mode grouping effect (quasiperiodic spectral modulation). Secondly, first experimental studies of quantum dot intermixing are reported, suggesting that this technique is capable of both improving the performance of active QD media and integrating active QD sections with passive waveguides