Large modular expandable optical switching matrices

Large optical switching matrices can be assembled incrementally from identi cal modules by means of a rearrangement of the Clos architecture that we ha ve labeled SKOL. The design retains the strict-sense nonblocking properties of the Clos design, identical units provide economies of manufacture, and there are also cost advantages associated with the incremental expandabilit y. SKOL modules can be constructed in ways that do not map back to the Clos or iginal. In this form, SKOL is a new multistage switching architecture that is well adapted for construction with integrated optical technologies. We a nticipate that the SKOL design can provide the very large, expandable optic al switching matrices now demanded for optical networks.