Prospects brought by optical amplifiers in repeaterless submarine systems

Erbium-doped fiber amplifiers (EDFAs) have seen rapid developments in the past few years, and they are now particularly well suited for repeaterless submarine links, which aim for even longer spans. An EDFA can be used to increase the transmitter output power. At the receiver end, an EDFA can be used as a preamplifier, either at the receiver site or at some distance with remote pumping, in order to obtain a better gain/noise compromise. With such amplifiers, commercial systems up to 300 km at 622 Mb/s or 260 km at 2.5 Gb/s can be implemented.<
>