Advances in modeling and optimization for two-photon lithography

Metasurfaces have become a key focus in research and are applied in numerous fields because of their exceptional capability to control electromagnetic waves across microwave to optical frequencies. These artificial sheet materials have the advantages of lightweight and ability to control wave propagation both on the surface and in the surrounding free space. The complexity of fabricating metasurfaces via two-photon lithography (TPL) is addressed through sophisticated modeling. Critical to the success of TPL is the ability to predict the effects of the fabrication process on the final product. This paper introduces three distinct modeling approaches that vary in complexity and predictive capabilities. We evaluate the performance and limitations of a simple threshold model, a compact model and a full model of polymerization. Through application examples, we demonstrate how these models can guide the fabrication of metasurfaces.