A BLACK-BOX MODEL OF EDFAS OPERATING IN WDM SYSTEMS

A black box model is derived for an erbium-doped optical amplifier and is successfully applied to 1480 and 980 mn pumped devices operated un der conditions which are typical for wavelength division multiplex (WD M) systems. It allows compound optical amplifiers with arbitrary passi ve optical circuitry (isolators, couplers, taps, and equalizing filter s) to be modeled on the basis of ''black box'' characteristics. The ga in model is based on an analytic solution for the effective two-level laser system, i.e., it is equivalent with the results of most numerica l EDFA modeling tools. The model for amplified spontaneous emission (A SE) based on an equivalent ASE source in front of the amplifier can be applied over a aide range of operating points.