Date Added: Dec 2009
The ubiquitous presence of the multimedia applications and the tremendous popularity of the World Wide Web have dramatically increased the amount of traffic over the Internet, which creates the urgent requirement for high bandwidth links and switches. Due to the progress in DWDM technology, link bandwidth for carrying such traffic is no longer a problem. For DWDM networks, Optical Cross-Connect (XOC) in nodes are key functional elements that steer whole network traffic by simultaneously switching a huge amount of optical flows. To build a large-scale OXC, generally small (e.g 2x2) switching elements (e.g. Directional couplers) are used as the basic building blocks, and are interconnected in a particular fashion to satisfy the required connectivity.