Design and performance of the fsa submarine optical amplifier system

The FSA submarine optical amplifier system (submarine fiber using optical amplifiers) has been developed. It can transmit signals up to 10 Gbit/s with a repeater spacing of 100 km. The submarine repeaters contain optical amplifiers for six line pairs to yield a maximum capacity of 60 Gbit/s. This paper describes its system configuration, the repeater configuration, and the fiber dispersion management scheme used to realize bit‐rate flexible transmission and in‐service monitoring. In long‐haul optical amplifier systems, since the amplified spontaneous emission noise from the optical amplifier is the main impairment limiting the transmission distance, an SNR design technique that takes this noise into account is developed. Finally, the results obtained after the commercial installation of this system in the Kagoshima‐Okinawa route (total length 905 km) are reported, including chromatic dispersion characteristics and SNR values at both 2.5 Gbit/s and 10 Gbit/s transmission. The effectiveness of the system design is verified through the demonstration of good transmission performance and the feasibility of in‐service monitoring.