1. A method for optimizing the routing of a data stream using Asynchronous Transfer Mode (ATM) over an optical network employing Space Division Multiplexing, wherein said network comprises a plurality of nodes interconnected by physical links comprised of a plurality of optical fibers suitable for carrying data at a common carrier wavelength, said method comprising the steps of: determining the number of hops for a plurality of logical links between pairs of said nodes, wherein each logical link is associated with a distinct Virtual Path Channel (VPC); assigning a first of said plurality of optical fibers to each logical link having only one hop; and for each logical link having more than one hop, i) employing a non-deterministic algorithm with the objective function of minimizing the total number of hops to separate each logical link into a sequence of logical link portions, or Virtual Path Links (VPLs); ii) selectively grouping at least a first VPL associated with a first VPC with a second VPL associated with a second VPC to form Virtual Paths (VPs) between adjacent ones of said nodes; and iii) assigning a second of said plurality of optical fibers to each said VP.