Design principles of all-optical multilayer switches

Problems arising throughout the design of 3D lightwave circuits are briefly addressed in the following. (1) The implementation of M X N-gon switches. (2) The routing of M X N-gon prism switches and (3) the routing of all- optical 3D girds and (5) dual switches. (6) The improvement of the switches towards the crossbar and (7) the generalization of all-optical grids to any N >= 3.