On-Chip Metasurface-on-Facets for Ultra-High Transmission through Waveguides in Near-Infrared

Eran Falek, Aviad Katiyi, Yakov Greenberg, Alina Karabchevsky

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


Nature has long inspired scientists and engineers to develop transparent surfaces via constructing anti-reflective surfaces. In absence of anti-reflection (AR) coating, silicon reflects about 35% of light for a single interface air−silicon. Here, inspired by jellyfish anti-reflective eyes, a man-made anti-reflective surface on the facet of the waveguide is proposed and demonstrated for waveguides transparency in near-infrared. The optimized metamaterial with unit cells of 560 × 560 nm shows transparency of 2.6 times better as compared to the waveguide with blank facet. Metasurfaces are milled on the waveguides facets with a focused ion beam. Silicon-on-insulator waveguides are tested with an inline set-up. Far-field scattering diagrams reveal that it is the special geometry of the unit cells of the engraved metamaterial, which can be associated with the directional scattering resulting in combined effect: on one hand the ultra-high transparency of the device and on the other hand the efficient coupling to the low-order modes due to the focusing dielectric nano-antennas effect. Reported here waveguide facets as AR metamaterials on a chip, opens up opportunities to engineer transparent on-chip devices with high coupling efficiency for diverse applications from sensing to quantum technologies.

Original languageEnglish
Article number2100130
Pages (from-to)1-8
Number of pages8
JournalAdvanced Optical Materials
Issue number11
Early online date24 Apr 2021
StatePublished - 4 Jun 2021


  • anti-reflection vertical bar anti-reflective metasurfaces
  • all-dielectric nanophotonics
  • gradient index
  • integrated photonics
  • silicon waveguides

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics


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