Multiplane optical fabrics for Terabit packet switches

This paper considers the use of optical fabrics to interconnect linecards in Terabit packet switches and routers, in order to overcome some of the limitations of current electronic realizations. In a previous paper [1] we considered WDM passive optical interconnection architectures that exploited a broadcast-and-select approach and wavelength agility at linecards to implement the required switching functionality. A non-trivial modeling of the used optical components, based upon the characteristics of commercially available devices, showed that aggregate capacities in the order of few Terabits are possible in very simple single-plane optical switching fabrics. This paper extends the approach toward multiplane, single-hop, optical interconnection architectures, which add the space dimension to the wavelength one for multiplexing packets to be transfered from input to output linecards. Our scalability analysis shows that the multiplane approach does not gain much in terms of aggregate capacity due to the need for space switches (realized with Semiconductor Optical Amplifiers - SOAs), but, as expected, reduces significantly the wavelength agility requirements of tunable devices, making the overall design more feasible.