A study on function expansion based topology optimization method for dispersion property

In this paper, the function expansion based topology optimization is employed to the optimization of the waveguide dispersion property and the optimum design of low-dispersion slow-light photonic crystal waveguides (PCWGs) is demonstrated. In order to realize low-dispersion and large group index, the objective function to be optimized is expressed by the weighted sum of the objective functions for the desired group index and the low-dispersion property, and the weighting coefficients are updated through the optimization process.