678 Mbaud optical transmission experiment through 37 km of PCVD graded-index fibre

A 5B6B line-coded 565 Mbit/s system designed for single-mode transmission at 1.3 ¿m wavelength was successfully operated through 37 km of state-of-the-art graded-index fibre (50/125 ¿m) made by PCVD process. With mean bandwidth values in excess of 1.5 GHz for the individual 2.18 km-long cable sections and a low concatenation factor (¿¿0.54), an overall fibre bandwidth of 400 MHz was achieved. The measured receiver sensitivity was ¿32.5 dBm for a 10¿10 BER, showing a penalty of ¿3 dB compared to single-mode transmission.