Level set-based topology optimization for anti-reflection surface

We present a level set-based topology optimization method to model anti-reflection surfaces (ARSs). An objective functional is defined as an integration of scattering intensity of an electric field, and the ARSs are optimally designed by minimizing reflections at the air-dielectric interface. During the topology optimization, geometric constraints are controlled by adjusting a regularization parameter. The performance of the ARSs improves as the value of the regularization parameter becomes small. Level set functions are used to express dielectric structures, and dielectric boundaries are interpreted as lines on the iso-surface of the level set functions.