Vectorial Metasurfaces Designed via Identical-Scatterer and Intelligent-Algorithm Schemes for Free Manipulation of On-Chip Sources.

Abstract

Metasurfaces have exhibited huge potential for manipulating fields of on-chip light sources. It is known that the scattering properties of nano-scatterers depend not only on the diverse incident directions of the excited in-plane waveguide modes but also on the in-plane orientations of nano-scatterers. This greatly complicates the design of metasurfaces for freely manipulating fields of on-chip light sources. Herein, we propose an identical-scatterer scheme to make the scattering properties of each nano-scatterer independent of the various in-plane incident directions of on-chip sources. Then, a self-discretizing iterative computational holographic intelligent algorithm is developed to arrange identical nano-scatterers to create vectorial metasurfaces for free manipulation of on-chip sources. Experimentally, we demonstrate not only eight independent emission beams, each with its own emission direction and polarization state, exhibiting round and near-diffraction-limited profiles (divergence ≈ 1.0°) with high polarization purities (91%-99%), but also complex emission patterns with different emission directions and polarization states.