Wavelength-routed optical networks using coherent transmission

The authors consider future networks in which the electronic switches are replaced by passive optical nodes, using the 50-THz bandwidth of silica fiber to provide an optical ether with communications routed by wavelength. They identify a class of such networks which would use coherent transmission for wavelength selectivity, and optical amplifiers for simple multiwavelength repeaters. The motivation to investigate and develop these technologies thus stems from the potentially large reductions in the cost of switching, rather than the diminishing returns on transmission. The practicability and scope of such networks are considered.<>