Fig. 1. Design methodology to create the broadband LWIR meta-optics.

a Our objective is a LWIR meta-optic that focuses broadband light at the same focal plane. b Parameterization of the complex (red) and the simple (blue) scatterers. For the complex scatterers, three variable parameters control the binary profile, namely, p₀, p₁, and p₂. This method of parameterization ensures 4-fold symmetry of the geometry, thus ensuring polarization-insensitivity. The height h is kept constant at 10 μm. The meta-atoms sit on a square lattice with a periodicity Λ set to 4 μm. c Block diagram of the optimization routine. d The simulated Strehl ratio of the simple, complex, and hyperboloid meta-optic where perturbations are introduced to simulate the imperfections inherent in the fabrication process.