Combined Metagratings for Efficient Broad-Angle Scattering Metasurface

Verena Neder, Younes Ra'Di, Andrea Alù, Albert Polman

Research output: Contribution to journalArticlepeer-review

40 Scopus citations


Spectrally controlled diffusion and reflection of light are key operations for light management in many optical devices. Integration of this operation in complex nanophotonic devices requires a 2D interface that provides tailored spectrum and directivity control. Here, we present a metagrating superstructure that realizes a resonant light reflector with tailored angular scattering profile. Millimeter-sized metasurfaces are built from arrays of combined supercells of 20-50 μm, composed of 5-7 differently pitched metagratings that tailor at will and with large efficiency the angular response. Each supercell is composed of one or more Si Mie resonators, arranged in a periodic array above an Ag back plane and tailored to resonantly scatter light at 650 nm into only the ±1 diffraction orders with very high efficiency. By varying the pitch and supercell design, we can tailor the overall metasurface reflection profile with large flexibility, realizing a broad-angle Lambertian-type scattering metasurface, as well as a large-angle (35-75°) scattering metasurface, both with resonant optical scattering efficiencies above 70%. These ultrathin structures, fabricated using thin-film deposition, electron beam lithography, and reactive ion etching, can find applications for light trapping and spectrum splitting in solar cells and other devices.

Original languageEnglish (US)
Pages (from-to)1010-1017
Number of pages8
JournalACS Photonics
Issue number4
StatePublished - Apr 17 2019
Externally publishedYes


  • Lambertian scattering
  • Mie resonances
  • dielectric nanoparticles
  • metagrating
  • spectrum and angle control

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering
  • Biotechnology


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