Chapter 6 - Optical Backplanes, Board and Chip Interconnects

Abstract

This chapter provides an insight of rapidly advancing field of research into optical interconnects within data processing systems ranging from the interframe down to the interchip level. The chapter describes the 10 Gbit/s data rate regime at the intersystem level. These are essentially high-speed 850-nm vertical-cavity surface-emitting lasers, parallel optical links, and new-generation silica as well as plastic optical multimode fibers. For all these categories, the available technology options and practical examples are also presented. The optical interconnects are usually categorized into distinct categories: frame-to-frame, board-to-board, multi-chip module (MCM)-to-MCM, chip-to-chip on a single MCM, and intra-on-chip. High-performance intersystem links generally employ well-established graded-index silica multimode fibers and approach 10 Gbit/s per channel signaling rates. Continued development of high-bandwidth plastic optical fibers can bring further cost savings in certain application areas. Optical chip interconnects are important in terms of realization of new computing architectures exploiting massively parallel three-dimensional off-chip data transport. Over a shorter timeframe, the focused efforts being made in the fields of heterogeneous integration and packaging can result in very compact transceiver modules for space-parallel two-dimensional data communication.