Figure 3:

Performance of quadratic metalenses.

(A) Fourier transform spectra of the wide-angle metalens for an NA of 0.4 (black), 0.65 (blue), and 0.9 (red), for normal incidence. (B) Same as the red line in (A), but for oblique incidence. Adapted with permission from ref. [85]. Copyright 2020, American Chemical Society. (C–D) Position of the light axis projected onto two kinds of landscape quadratic metalenses after passing through the aperture stop for the configuration of Figure 2C and E, assuming that the refractive index of the dielectric gap is equal to 1.45.