Optoelectronics-VLSI system integration: Technological challenges

Hybrid VLSI-optoelectronics, also called smart-pixel technology, exploits the respective strengths of optics and electronic processing for the production of optical information processing systems of high performance. The recent integration of micron-size optoelectronic components such as emitters, photodetectors and spatial light modulators within VLSI electronic chips allows the fabrication of on/off chip data communication rate systems of the order of 1012 pin-Hz. This aggregate rate is at least one order of magnitude higher than is presently achievable in electronics alone. Several issues, however, remain to be resolved in order to fully benefit from this technology. These include the relevance of optics in information processing in general and computer science in particular, the design and choice of the logic complexity of the electronic circuitry, its interfacing with optoelectronic components, the assembly and testing of the resulting systems. These technological challenges are discussed in this article in the light of the rapid progress achieved in this field.