1.55 μm optical transmission experiments at 2 Gbit/s using 51.5 km dispersion-free fibre

The high sensitivity of a Ge APD optical receiver, and dispersion-free fibres at a minimum loss wavelength of 1.55 μm, made it possible to achieve 51.5 km optical signal transmission at 2 Gbit/s. The optical receiving level was −31.4 dBm at a 10−9 error rate, and the degradation caused by fibre dispersion was only 0.6 dB. A data-rate repeater-spacing product of 103 (Gbit/s)km was achieved at 1.55 μm.