RESUMEN
Absorption and stimulated emission coefficients for a pump power at 1480 nm are determined experimentally for three types of erbium-doped silica fiber. Starting from these coefficients and using previous gain measurements, we calculate absorption and stimulated emission cross sections of the erbium laser transition. The results obtained are in good agreement with the ones that appear in the literature.
RESUMEN
Gain measurements are carried out for different lengths of three types of erbium-doped silica fiber with different pump powers at 1480 nm. From these measurements a relation is established for each type of fiber between gain and the attenuation factor of the pump power. This relation is in complete agreement with the one predicted by an analytic model based on overlapping factors, which makes it possible to obtain methods for the experimental characterization of doped fibers.
RESUMEN
Rate equations based on intensity-dependent overlapping factors are integrated to obtain analytic solutions for pump, signal, and amplified spontaneous emission (ASE), even when the coupled signal varies with time. The equations can be applied without the imposition of any restraints on the values of the pump, signal, and ASE powers, the excited-state-absorption cross section, the erbium-density distribution, or other parameters that characterize the fiber. The methods used to calculate pump, signal, and ASE powers are discussed. Experimental techniques to characterize the doped fiber that were based on these analytic expressions are introduced.
RESUMEN
A simple model describing the evolution of pump, signal, and amplified spontaneous emission powers in an erbium-doped silica fiber is presented. The model is based on overlapping factors, depending on pump- and signal-coupled powers, which are systematically studied. Accurate results for gain and amplified spontaneous emission are obtained when this model is used. Experiments to measure the characteristic parameters of the fiber appearing in the model are described. Two main advantages of this model are found: computation time is considerably reduced and fiber characterization does not make it necessary to measure the parameters of the fiber as a function of radial or azimuthal coordinates.