Transmission of 4.5 Gbit/s via a 36 km monomode fiber at 1550 nm

A 4.5 Gb/s optical transmission system has been developed for experimental use that is based on input and output bit rates of 139.264 Mb/s. To span the maximum regenerator spacing of 36 km, the system works at 1550 nm, using a single frequency DFB (distributed feedback) laser, standard monomode fiber, and ternary avalanche photodiode. Multiplexing and demultiplexing are effected in several steps: the frame structure of the first multiplexing level (565 Mb/s) can be maintained just by modifying the frame alignment word of one 565 Mb/s channel. Signal processing is done predominantly with GaAs-circuits; some Si ICs are used at the highest bit rate.<
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