One of the promising lightwave network architectures is the multihop lightwave networks based on wavelength division multiplexing (WDM). In this architecture, separate channels created by assigning different wavelengths between node pairs define the logical connectivity. This logical topology is independent of the underlying physical topology and can be adaptively changed according to the changing traffic patterns and connectivity requirements. One of the possible objectives for designing this logical topology is minimizing the maximum utilization on any link by choosing the logical connectivity and finding the optimum routing. This paper describes an algorithm based on simulated annealing for solving the joint logical topology design and routing problem. Different algorithms were implemented for the cases with bifurcated and shortest path routing. Computational experiments showed that the simulated annealing solutions are as good as or better than the solutions found in previous studies.