Optimum Non-Blocking Networks for Photonic Switching

We systematically minimize the number of elements in an NxN cross-connect consisting of 2x2 elements. The results are important for they optimize for the first time a wide-sense nonblocking cross-connect switch. The optimization covers all cases of interest, including dilated networks with minimal cross-talk, and it minimizes the number of elements, optimizing at the same time other properties such as depth and width. The control algorithm is straightforward in all cases.