1.55 /spl mu/m erbium-doped fiber amplifiers

Fiber amplifiers based on erbium continue to provide more capacity for long haul and access networks as improvements in component performance and system design are realized. High signal powers are required to extend span lengths or to provide more wavelength channels. Available signal powers, now approaching 1 Watt (30 dBm), have been achieved using erbium amplifiers with higher pump power, bi-directional or multistage designs and improved erbium doped fiber conversion efficiency. A variety of pump sources are now available for these applications.