160 Gb/s OTDM networking using deployed fibers

This paper reports a 160-Gb/s OTDM network comprising switching and demultiplexing through field deployed fiber. The 160-Gb/s signal was obtained by time-interleaving 16 channels of a 10-Gb/s signal. The add-drop node was realized by using a gain-transparent operation of a semiconductor optical amplifier (SOA). A subharmonic clock recovery with a prescaled electrooptical phase locked loop employing an electroabsorption modulator was applied. An OTDM receiver employed a four-wave mixing principle in an SOA. The impact of fiber chromatic and polarization-mode dispersion (PMD) is discussed. Switching and demultiplexing performance are shown for a fiber link of 275 and 550 km, respectively. Excellent operation of clock recovery, drop-through-add function, and transmission was achieved.