Contents I. Introduction
The steady increase in network traffic, driven primarily by data applications, is creating constant pressure to develop higher capacity transport and routing systems. While the transport side of the network has managed to support the rising bandwidth demands, mostly due to the deployment of dense wavelength-division multiplexing, electronic packet switching could become a serious bottleneck in the near future. Limited port density on router line cards necessitates multiple-rack systems for large routers. These multiple racks of line cards require a switch fabric and interconnections up to tens of meters at very high data rates. Optical switch fabrics based on wavelength switching can provide both switching and high-data-rate interconnection while retaining a passive optical backplane [1].
