Reflectance and reflectance anisotropy spectroscopy (RAS) were used to control in-situ the complex MOCVD growth process of both InGaAs/GaAs quantum dots (QDs) and lasers with such QDs in the active region. Spectra and transients yield online information on details of quantum dot and cavity formation, like InGaAs monolayer deposition prior to QD formation and evolution of the cavity resonance. The data were used to develop laser devices including the first electrically driven vertical cavity surface emitting QD laser (QD VCSEL) grown by using MOCVD. (C) 2004 Elsevier B.V. All rights reserved.