Transmission of a true single polarisation 40 Gbit/s soliton data signal over 205 km using a stabilised erbium fibre ring laser and 40 GHz electronic timing recovery.

Four independently modulated 10 Gbit/s channels were transmitted over 205 km with a penalty of less than 1.5 dB. The pulse source comprised a stabilised 10 GHz erbium fibre ring laser, multiplexed to 40 Gbit/s in a single polarisation by four independent lithium niobate modulators. Following transmission the requirement to kick start the demodulator is avoided using a 40 GHz electronic clock recovery circuit with a 10 GHz output. The experiment is performed entirely with commercial components and semiconductor laser diodes.