Bidirectional 10-channel 2.5 Gbit/s WDM transmission over 250 km using 76 nm (1531–1607 nm) gain-band bidirectional erbium-doped fibre amplifiers

The widest, seamless, 76 nm (1531–1607 nm) 3 dB gain-band bidirectional amplifier is realised by combining an erbium-doped fluoride fibre amplifier (1531–1562 nm) and a gain-flattened erbium-doped silicate fibre amplifier (1562–1607 nm) in a novel configuration of gain-band separation between upstream and downstream signals. Bidirectional 10-channel WDM transmission at 2.5 Gbit/s over a 250 km conventional singlemode fibre is successfully demonstrated using our amplifiers as two bidirectional repeaters.