Soliton propagation without transmission control using a phase-locked erbium fibre ring laser

2.5 Gbit.s/sup -1/ solitons have been transmitted a distance of 17600 km in a recirculating loop without transmission control. To achieve this a new stabilisation technique for modelocked erbium fibre lasers has been implemented. Cavity length changes are tracked with an electronic phaselock loop and the phase of the RF drive-adjusted accordingly.