Figure 1.

Dispersion properties of chromatic metasurfaces and schematic of the achromatic metalens. (a) Angular dispersion of the metasurface grating; (b) dispersion of polychromatic light incident at the edge of the chromatic metalens; (c,d) ray tracing of light at different coordinates; (e) schematic of the achromatic metalens in the LWIR range. In (a) through (d), the red ray represents light at ${\lambda }_{\max }$, the yellow ray represents light at ${\lambda }_0$, and the blue ray represents light at ${\lambda }_{\min }$. On the right is a schematic of meta-atoms, where H is the height of the nanopillar, and p is the period of the nanopillar. All meta-atoms have the same height and period.