  Conventional imaging systems comprise large and expensive optical components
which successively mitigate aberrations. Metasurface optics offers a route to
miniaturize imaging systems by replacing bulky components with flat and compact
implementations. The diffractive nature of these devices, however, induces
severe chromatic aberrations and current multi-wavelength and narrowband
achromatic metasurfaces cannot support full visible spectum imaging (400-700
nm). We combine principles of both computational imaging and metasurface optics
to build a system with a single metalens of NA ~ 0.45 which generates in-focus
images under white light illumination. Our metalens exhibits a spectrally
invariant point spread function which enables computational reconstruction of
captured images with a single digital filter. This work connects computational
imaging and metasurface optics and demonstrates the capabilities of combining
these disciplines by simultaneously reducing aberrations and downsizing imaging
systems with simpler optics.
