Penalty-free bidirectional transmission of 4/spl times/10 Gbit/s signals over 88-km of true-wave fiber using an in-line semiconductor optical amplifier

Summary form only given.The semiconductor optical amplifier (SOA) is a promising candidate for cascaded optical fibre systems because of the coverage of the entire fiber transmission window and the possibilities for integration and low cost. Bi-directional transmission can utilize efficiently the optical fiber transmission bandwidth and reduce the complexity and cost of optical transmission systems and networks. SOAs as optical switches or in-line amplifiers are very suitable for bidirectional transmission systems and networks since SOAs do not need any optical isolators as often used in case of erbium-doped fiber amplifiers (EDFAs). In this paper, we report error-free bidirectional transmission of 4/spl times/10 Gbit/s signals using an in-line SOA. In order to reduce the intermodal distortion and cross talk in SOAs, one can operate SOAs in the small signal region or implement gain control schemes such as damping the gain of SOAs.