Dispersion in rare-earth-doped fibers.

Rare-earth dopants in optical fibers have in general been ignored as a source of dispersion. The host material dispersion has been assumed to be an adequate description of the dispersion properties. Resonant dispersion features owing to absorption by the rare-earth ions were observed that were comparable in magnitude with the host material dispersion. These observations have consequences in the design of fiber lasers, nonlinear fiber transmission systems, and analog information systems.