Supplementary Material: The Diffractive Achromatull Spectrum Computational Imaging with Diffractive Optics

As has been discussed in main text, we use a designed initial guess derived from a mixture of a series of Fresnel lenses’ profiles for different wavelengths. Without loss of generality, we take an amplitude-type Fresnel zone-plate (FZP) as the instance for principle illustration. Leveraging scalar diffraction theory, the complex amplitude of a point at the image plane is the sum-up of all complex amplitudes derived from all sub-waves emitted from ring-zones of a FZP. To obtain constructive interference at the image plane, the zones should switch from the opaque to transparent at radius