Photonic cavity design by topology optimization

This study considers a recently proposed topology optimization based approach for designing photonic membrane cavities supporting a dipole cavity mode. Foremost, the study demonstrates that the approach is robust towards the choice of initial guess provided for the optimization problem, in the sense that near identical final designs are obtained for vastly different initial guesses. This finding suggests that the final designs are near-optimal under the given design constraints. Secondarily, by stopping the design procedure after the same fixed number of design iterations for all initial guesses, it shows that the designed photonic cavity is sensitive towards certain small perturbations of their geometry, stressing the need for utilizing robust optimization techniques and imposing fabrication conforming length-scales in the cavity geometries.