Broadband fiber amplifiers

Summary form only given. Wavelength-division multiplexing (WDM) transport networks require amplifiers allowing large channel counts along with large span distances. This means that high gain (>25 dB) and large output power is required, along with low noise figure, in order to ensure high channel signal-to-noise ratio. Hence, for a 2.5-Gbit/s line-rate, in the case of an Er-doped six-amplifier chain with 120-km spacing, an output power per channel of the order of +5 dBm is required.