1. A method of determining a shortest path between a source node and a destination node in an optical network having plural network nodes interconnected with optical transmission links, the method comprising: representing the network as a uni-directional graph G&equals;<V,E> with V defining a set of network nodes and E defining a set of uni-directional optical transmission links; transforming the graph G to a wavelength graph G′&equals;<V′,E′> with V′ defining a set of electronic nodes and optical channel nodes corresponding to the network nodes in set V and with E′ defining a set of internal links and optical channel links, the optical channel links corresponding to the optical transmission links in set E; and applying a single-source shortest path algorithm to the graph G′ to determine a shortest path corresponding to an optimal path on graph G.