Physical geometry and optical properties of objects are correlated: cylinders focus light to a
line, spheres to a point and arbitrarily shaped objects introduce optical aberrations. Multi …

Freeform optics aims to expand the toolkit of optical elements by allowing for more complex
phase geometries beyond rotational symmetry. Complex, asymmetric curvatures are …

The depth of focus of an imaging system determines the range of change for both the
position of focal plane and image plane. Although a typical light sword optical element with …

Dielectric metasurfaces are two‐dimensional structures composed of nano‐scatterers that
manipulate the phase and polarization of optical waves with subwavelength spatial …

Conventional optical components such as lenses, waveplates and holograms rely on light
propagation over distances much larger than the wavelength to shape wavefronts. In this …

Metasurfaces have facilitated the replacement of conventional optical elements with ultrathin
and planar photonic structures. Previous designs of metasurfaces were limited to small …

Recent rapid progress in metasurfaces is underpinned by the physics of local and nonlocal
resonances and the modes coupling among them, leading to tremendous applications such …

Flat optical components based on metasurfaces will appear in our daily life in the near
future. Our discussion focuses on metasurface-based components consisting of sub …

Optical metasurfaces, capable of manipulating the properties of light with a thickness at the
subwavelength scale, have been the subject of extensive investigation in recent decades …

The overall size of an optical system is limited by the volume of the components and the
internal optical path length. To reach the limits of miniaturization, it is possible to reduce both …