In this work, optimal assignment of full range wavelength converters have done over available nodes in wavelength division multiplexing optical network to maximize the total utilization of deployed converters. This will increase the performance by cost ratio by keeping the deployed converters busy maximally. The optimization model has solved by heuristic method to search the solution space efficiently through self adaptive form of differential evolution. A mechanism has also proposed to handle the dynamic utilization under the same network through maintaining the diversity in the population by insertion of a new member in each generation.