Computational Modelling of Metasurfaces for Strongly Divergent Beams

The control of light by means of metasurfaces with subwavelength building blocks has been explored in the last few years, giving rise to unprecedented functionalities [1,2]. Thin flat lenses and other optical components have been obtained by engineering the building blocks of metasurfaces. However, most metasurfaces realized so far are essentially designed to modify plane waves [3–5]. While the manipulation of nonplanar wave fronts is encountered in a diverse variety of applications, their control using metasurfaces is still in its infancy. Here we showcase the computational tools to design metasurfaces that can also manipulate strongly divergent light beams.