Abstract

The IBM System/390 :sup.*:esup. family of mainframe computers is among the first in the computer industry to use fiber optic I/ O channels for high speed data transfer. Known as ESCON (Enterprise Systems Connection) :sup.*:esup channels, these optical links provide significantly higher bandwidth, data rates, and distance than the parallel electrical cables which they replace. The ESCON :sup.*:esup. channels consist of 200 Megabit/s duplex fiber optic links (17 Megabytes/s). Multimode links using 1300 nm LED transmitters and PIN photodiode receivers allow a maximum unrepeated distance of 3 km using 62.5 micron core fiber and 2 km using 50 micron core fiber with a minimum modal bandtvidth of 800 Mhz-km. A single-mode version using InGaAsP laser diodes increases the unrepeated distance to 20 km while maintaining international class 1 laser safety. This paper describes the optical, electrical, and mechanical design innovations of the ESCON :sup.*:esup. channels. Optical link budget modeling will be discussed, as well as design of a duplex optical connector and cable strain relief system. Experimental data will be presented on link performance in harsh environments such as elevated levels of ionizing (gamma) radiation, or customized link designs which can extend the maximum unrepeated distance.

© 1993 Optical Society of America