Erbium-doped fibre amplifier circuit having a subsidiary erbium-doped fibre useful for bidirectional optical transmission systems

摘要

An Er/sup 3+/-doped fibre amplifier circuit is proposed for use at a terminal end of bidirectional optical transmission systems which use wavelengths in the 1.53 mu m and l.55 mu m bands. A subsidiary Er/sup 3+/-doped fibre to compensate for the gain characteristic difference between these wavelengths allowed nonrepeated bidirectional transmission at 2.488 Gbit/s with a 49 dB power budget margin.