Suppression of output power and NF excursions in cascades of highly inverted EDFAs with packet-switched traffic

Significant output power excursions in cascades of erbium-doped fiber ampli fiers (EDFAs) can cause serious problems in wavelength division multilexing (WDM) packet-switched burst-mode networks. Signal power excursions more se rious than those induced by channel addition/removal in circuit switched ne tworks can arise when data on the WDM channels is highly variable in nature . Self-similar traffic can be subject to large variation in EDFA gain. In o rder to prevent unacceptable error bursts, due, for example, to channel pow er becoming too low to preserve adequate eye opening or exceeding threshold s for optical nonlinearities, the channel power should be maintained consta nt. In this letter, it is shown that the sizable power and noise figure swi ngs arising in a cascade of EDFAs with WDM burst-mode packet-switched netwo rks with self-similar traffic can be effectively suppressed when highly inv erted amplifiers are employed. The analysis is based on the application of a numerical model, which solves the transcendental equation for length aver aged metastable level population of an EDFA.