Robust optimization in electromagnetic scattering problems

In engineering design, the physical properties of a system can often only be described by numerical simulation. Optimization of such systems is usually accomplished heuristically without taking into account that there are implementation errors that lead to very suboptimal, and often, infeasible solutions. We present a robust optimization method for electromagnetic scattering problems with large degrees of freedom and report on results when this technique is applied to optimization of aperiodic dielectric structures. The spatial configuration of 50 dielectric scattering cylinders is optimized to match a desired target function such that the optimal arrangement is robust against placement and prototype errors. Our optimization method inherently improves the robustness of the optimized solution with respect to relevant errors and is suitable for real-world design of materials with unconventional electromagnetic functionalities, as relevant to nanophotonics. © 2007 American Institute of Physics. DOI: 10.1063/1.2715540