  Metasurfaces are subwavelength-thick constructs, consisting of discrete
meta-atoms, providing discretized levels of phase accumulation that
collectively approximate a designed optical functionality. The meta-atoms
utilizing geometric phase with polarization-converting structures produced
encouraging implementations of optical components including metalenses.
However, to date, a pending and fundamental problem of this approach has been
the low device efficiency that such resulting components suffer, an unwanted
side effect of large lattice constants used for preventing inter-coupling of
their meta-atoms. Although the use of near-field coupling for tuning
electromagnetic resonances found its use in constructing efficient narrow-band
designs, such structures fell short of providing high efficiency over a broad
spectrum. Here, we propose and show that tightly packed fabric of identical
dielectric nanopillar waveguides with continuously-tuned inter-coupling
distances make excellent and complete achromatic metasurface elements. This
architecture enables the scatterers to interact with the incoming wave
extremely efficiently. As a proof-of-concept demonstration, we showed an
achromatic cylindrical metalens, constructed from strongly coupled dielectric
nanopillars of a single geometry as continuously-set phase elements in a
'meta-atomless' fashion, working in the entirety of 400-700 nm band. This
metalens achieves over 85 percent focusing efficiency across this whole
spectral range. To combat polarization sensitivity, we used hexagonally stacked
nanopillars to build up a polarization-independent scatterer library. Finally,
a circular metalens with polarization-independent operation and achromatic
focusing was obtained. This is a paradigm shift in making an achromatic
metasurface architecture by wovening identical nanopillars coupled into an
irregular lattice constructed via careful tuning.
