ABSTRACT
Optical communication technology continues to expand after many years of rapid growth. It was over
twenty years ago that Corning Incorporated (Kapron et al. 1970) demonstrated that the attenuation in
doped silica fiber was low enough that long-distance communication through optical fibers would be
advantageous over copper. Soon thereafter, fiber-optic systems proved feasible. In the 70’s, the first
commercial systems used multimode fibers to better capture the available light and because the state of
the art of the associate components was better suited for a large-core fiber. In the 80’s, long-haul
transmission proved, beyond a doubt, that fiber-optic transmission was a commercial reality. The use of
single-mode fiber with laser diodes enabled transmission rates to reach the gigabit-per-second rate over
tens of kilometers. Almost immediately, single-mode fiber replaced multimode fiber in trunk line
applications. Multimode fiber, however, found important applications in local area networks.
