Highly dispersed pulses for 2 × 40 Gbit/stransmission over 800 km of conventional singlemode fibre

Abstract
Two-channel 40 Gbit/s transmission over 800 km of conventional fibre is reported. Return-to-zero 2.5 ps pulses are used to minimise self-phase-modulation effects, enabling 80 km amplifier spacing, and allowing dispersion compensation to be carried out entirely at the receiver.