250 km nonrepeated transmission experiment at 1.8 Gb/s using LD pumped Er/sup 3+/-doped fibre amplifiers in IM/direct detection system

A nonrepeated fibre transmission experiment over 250 km is achieved at 1.8 Gb/s in a direct-detection repeater system using LD pumped Er/sup 3+/-doped fibre amplifiers as pre and postamplifiers. Repeater gain of 50 dB is accomplished.