Photonic switching applications of 2-D and 3-D crossover networks based on 2-input, 2-output switching nodes.

Optical implementations of both 2-D and 3-D crossover networks are described, and we show that these networks can be used for connecting multiple stages of 2-input, 2-output switching elements. We also show that simple conversion steps can be used to convert 2-D crossover networks into 3-D crossover networks. Both network types can be implemented with low loss optical imaging systems, and we show that the same optics can be used to implement the intranode connections and the internode for various types of 2-input, 2-output switching elements. In addition, we discuss the difficulties that arise when the same optical hardware is applied to switching elements of larger dimensionality.