COMPLEX FINITE-ELEMENT METHOD APPLIED TO THE ANALYSIS OF OPTICAL WAVE-GUIDE AMPLIFIERS

A complex finite-element method and a three-level model for Erbium ion s are applied to obtain gain and propagation constants for erbium-dope d waveguide amplifiers (EDWA's). The complex refractive index profile includes the effect of the dopant polarization induced by the pump fie ld, The method allows to consider arbitrary dopant density profile as well as the modal structure of the pump field. For different waveguide geometries we obtain gain curves as function of pump intensity as wel l as slight variations in the modal propagation constants, The thresho ld pump power is shown to be a function of the waveguide geometry, whi ch agrees qualitatively with experimental results.