Abstract

Several demonstrations of switches based on symmetric self-electro-optic-effect devices (S-SEEDs) have shown the advantages of using free-space optics for handling high interconneclion density at high bandwidth. The S-SEEDs were fabricated by using standard GaAs processing, but with MBE grown multiple quantum wells, to produce large arrays of devices that switch with picojoule energies. Since the S-SEEDs function solely as optical detectors and modulators, problems of reliability and heat generation of the optical power are removed from the chip. After several generations of S-SEEDs, progress stalled on further improvements in switching energy and therefore processing capacity. Smart pixels, cells containing optical inputs and outputs with some electronic processing localized to the cell, offered the possibility of extending the switching energy progress curve and enhancing the functionality of each cell of an array. FETs have been fabricated with S-SEEDs in compatible processes and have resulted in improved optical switches. There are tradeoffs, however, inherent (such as decreased density, suboptimized performance of both electronic and optical devices, and complexity of processing) that need to be considered in the design. Progress made in several generations of FET-SEED-based smart pixels and predictions of future trends will be presented.

© 1992 Optical Society of America