This compilation of review articles by leading experts presents clearly the trend in future optoelectronic devices. It is clear that optoelectronic and photonic integration help to further improve high-speed system capabilities and increase the total systems and network capacities with WDM technology. The foundation of the integration technology is based on quantum well materials, and advanced epitaxial growth and device processing techniques. The integrated laser/ modulators, multi-wavelength laser arrays, and OEIC receivers have demonstrated the feasibility of this technology, but much work remains to be done to put such technology to practice.