1111 km, two channel IM-DD transmission experiment at 2.5 Gb/s through 21 in-line erbium-doped fiber amplifiers

Two-channel transmission is demonstrated in a 2.5 Gb/s intensity-modulated direct-detection system over a distance of 1111 km, using 21 in-line erbium-doped fiber amplifiers. The two channels incur virtually no penalty when they are transmitted simultaneously. Owing to the use of gain filtering in the amplifiers instead of discrete in-line optical filters, the overall bandwidth of the link is about 15 nm, for a sensitivity penalty smaller than 1 dB on one single transmitted channel.<
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