  Optical components, such as lenses, have traditionally been made in the bulk
form by shaping glass or other transparent materials. Recent advances in
metasurfaces provide a new basis for recasting optical components into thin,
planar elements, having similar or better performance using arrays of
subwavelength-spaced optical phase-shifters. The technology required to mass
produce them dates back to the mid-1990s, when the feature sizes of
semiconductor manufacturing became considerably denser than the wavelength of
light, advancing in stride with Moore's law. This provides the possibility of
unifying two industries: semiconductor manufacturing and lens-making, whereby
the same technology used to make computer chips is used to make optical
components, such as lenses, based on metasurfaces. Using a scalable metasurface
layout compression algorithm that exponentially reduces design file sizes (by 3
orders of magnitude for a centimeter diameter lens) and stepper
photolithography, we show the design and fabrication of metasurface lenses
(metalenses) with extremely large areas, up to centimeters in diameter and
beyond. Using a single two-centimeter diameter near-infrared metalens less than
a micron thick fabricated in this way, we experimentally implement the ideal
thin lens equation, while demonstrating high-quality imaging and
diffraction-limited focusing.
