VLSI microphotonics: issues, challenges, and prospects

Abstract

This paper presents an overview of our study on the subject that we categorically termed VLSI (very large scale integration) microphotonics. We examine the scientific and technological issues and challenges concerning three essential steps in this technology: miniaturization, interconnection, and integration of microphotonic devices, circuits and systems in micron or submicron scale. In miniaturization, the issues on the size effect, proximity effect, energy confinement effect, microcavity effect, single photon effect, optical interference effect, high field effect, nonlinear effect, noise effect, quantum optical effect, and chaotic noise effect should be addressed. In interconnection, the issues of connecting identical devices (homogeneous interconnection) or nonidentical devices (heterogeneous interconnection) have to be examined. Optical alignment between micron-scale devices, minimizing interconnection losses, and maintaining optical modes between devices, are to be considered. In integration, the issues of interfacing same kind of devices, two different kinds of devices, and several or many different kinds of devices have to be addressed. Other issues include the design and packaging of the integrated devices and circuits as a system for reliable function and operation. In the course of this study, we closely follow the experiences of VLSI microelectronics so that they can provide lessons, learnings, and insights that microphotonics can benefit from. Similarities, dissimilarities, advantages, and disadvantages of the two technologies are explored in such a way that they can be more effectively utilized by mutual support and complement. Directions for future studies are also discussed.