Electric field distributions of a selection of metaatoms simulated with COMSOL Multiphysics. For both metamirror designs of Figure 7, we visualized 9 linearly spaced metaatoms along the diagonal from the center to the edge of the metamirror, i.e. at 1.5 mm distance. For three, the electric field distributions for all three spacial planes are shown for both (a) 1064 nm and (b) 1550 nm. The field distributions have been normalized across all 18 plots.