Evidence of a saturable-absorption effect in heavily erbium-doped fibers.

A new configuration for erbium-doped fiber lasers in which two different connected fibers are used is studied: one is heavily and the other weakly doped. It is demonstrated that the dynamics of such a system depends on the fiber into which the pump is injected. The experimental results are interpreted in the framework of an ion-pair interaction model.

Antiphase dynamics and chaos in self-pulsing erbium-doped fiber lasers.

We present experimental evidence of antiphase dynamics in self-pulsing erbium-doped fiber lasers operating simultaneously at 1.536- and 1.55-microm wavelengths. Autonomous chaos is also observed for several ranges of pumping rates. The fractal dimension of the chaotic attractor, calculated from experimental data by use of the Procaccia method, is found to depend on the pumping ratio but always remains smaller than 4.1, regardless of the chaotic regime considered.