Feature

Optical Interconnections in the '80s

Joseph W. Goodman

In the late 1970s and early 1980s, the spectacular contributions of fiber optics to long distance communication were motivating the examination of the use of the optics for solving interconnection problems at the highest levels of the interconnect hierarchy, namely at the processor-to-processor level. As early as 1979, Cathey and Smith had proposed a parallel free-space optical data bus for use within a computer. In 1981, Tajima, Okada, and Tamura proposed the development of free-space optical buses for a multiprocessor machine and, in 1983, these same authors reported development of an experimental freespace optical data bus running with a 100 MHz clock speed. Further advances on this project were described in following years; the computer in which this bus is used in often referred to as Dialog.H.