Self-routing of all-optical 2D switching networks

Routing of all-optical 2D switching networks (which connect 2D data whereas the networks span the 3D physical space) is more complex than routing of (planar) 1D networks mainly caused by the (1) combinatorial `explosion' and (2) the arising spatial all-optical >= 3 X 3-switches which are difficult to implement. The routing problem may be subdivided into ((alpha) ) the combinatorial problem of determining the k to generate arbitrary permutations of the inputs at the output of a (rearrangeable nonblocking) network and ((beta) ) the realization of the states of the all-optical >= 3 X 3- switches by the search for waveguide-electrode configurations and voltage adjustments where the paper concentrates on ((alpha) ). The 2D switching networks are (1) projected into plane graphs which--in turn--are (2) mapped onto hypercubes (N equals 4 and 6) and (3) routed by means of the algorithms of (2). Several routing concepts are reviewed and the introduction of several wavelengths is discussed.