  Metasurface optics have demonstrated vast potential for implementing
traditional optical components in an ultra-compact and lightweight form factor.
Metasurface lenses, also called metalenses, however, suffer from severe
chromatic aberrations, posing serious limitations on their practical use.
Existing approaches for circumventing such aberrations via dispersion
engineering are limited to small apertures and often entails multiple
scatterers per unit cell with small feature sizes. Here, we present an
alternative technique to mitigate chromatic aberration and demonstrate
high-quality, full-color imaging using extended depth of focus (EDOF)
metalenses and computational reconstruction. Previous EDOF metalenses relied on
cubic phase masks that induced asymmetric artifacts in images, whereas here we
demonstrate the use of symmetric phase masks that can improve subsequent image
quality, including logarithmic-aspherical, and shifted axicon masks. Our work
will inspire further development in achromatic metalenses beyond dispersion
engineering and open new research avenues on hybrid optical-digital metasurface
systems.
