A silicon-photonic integrated circuit comprising a direct-bandgap-semiconductor-based active optical device that is epitaxially grown on an indirect-bandgap SOI substrate (108) is disclosed. The structure of the active optical device includes an active region (120) having quantum dots (206) made of InGaAs that are embedded in one or more confinement layers (n-InP, p-InP), where the bandgap of the confinement layers is higher than that of the quantum dots. Further the confinement-layer material is preferably lattice matched to the quantum dot material in order to suppress associated crystalline defects within the material are located away from the center of its bandgap such that they suppress recombination-enhanced defect-reaction-driven degradation of the active optical device. The active optical device is epitaxially grown on a handle substrate of an SOI substrate that has a surface waveguide formed in its device layer, where the active region and the surface waveguide are at the same height above the handle wafer surface.