TRANSMISSION AND SATURATION PERFORMANCE OF DISPERSION-SHIFTED DISTRIBUTED ERBIUM FIBER

The gain spectra for a bidirectionally pumped 30 km length of lightly doped dispersion shifted erbium fibre and the amplification performance in saturation of a 54 km length of similar fibre are presented. The longer length comprised six spliced fibres with an average erbium concentration in the core of approximately 60ppb and could be rendered lossless with 2 x 30 mW of pump power for low power signals. With 2 x 55 mW of pump power a peak fibre gain of 17 dB at 1536 nm was realised; as the input signal power was increased the gain was suppressed but the fibre remained transparent for signal powers up to - 2 dBm.