The study of high density integrated optoelectronic circuits involves (a) the development of hybrid integration technologies and (b) the generation of models for the optoelectronic devices. To meet the first goal, a methodology for the heterogeneous integration of epitaxial GaAs wafers with fully processed standard bipolar complementary metal-oxide-semiconductor (CMOS) Si wafers, based on spin-on glass (SOG) /SiO2 bonding, is presented. Further investigation on heterogeneous integration is achieved by presenting a second methodology for the integration of a photonic layer above CMOS integrated circuits: a novel metallic bonding technique that utilizes the Au-20Sn eutectic alloy along with the rare earth element (Gd) is developed for the bonding of complete optoelectronic (OE) dies, consisting of optical sources, detectors and waveguides, to CMOS circuits. To meet the second goal, an efficient model scheme that combines the nonlinear behavior of the input parasitics with the intrinsic fundamental device rate equations of the vertical cavity surface emitting lasers (VCSELs) is proposed. A systematic methodology for the model parameter extraction is presented. Simulation results are compared with the experimental measurements while extraction and simulation procedures are implemented in commercial integrated circuit design tools. Finally, using the proposed model, the traditional laser diode driving (LDD) circuits have been evaluated for their suitability to drive VCSELs.