Abstract

The evolution of lightwave systems over the past decade has seen a drama tic charge in the constraints imposed by the transmission medium. This is best exemplified by the systemlimit curves shown in Fig. 1 for a 1550 nm digital system, circa 1983. Most notable among the changes to this figure in recent years is the elimination of the loss curve which limited unregenerated span lengths to below ~100 km prior to the development of the erbium-doped fiber amplifier. Today, span lengths of global dimensions are being demonstrated.

© 1993 Optical Society of America