Scalability of optical multiwavelength switching networks: crosstalk analysis

The scalability of optical multiwavelength switching networks with respect to bit rate, number of wavelength channels per fiber, and number of inputs/outputs per optical node is examined. The limits considered here are those imposed by the combination of interferometric crosstalk, optical noise accumulation, and optical amplifier gain saturation. An analytical model that combines these effects is described. For the class of optical cross-connects examined, the number of first- and second-order crosstalk contributions per node for different node architectures and node sizes is derived. The results show that with a carefully designed optical cross-connect architecture, it should be possible to construct a fairly large meshed all-optical network (more than ten nodes in diameter with 32 inputs/outputs per node and 32 wavelengths per fiber) if the crosstalk of optical space switches, multiplexers, and demultiplexers is about -30 dB.