Metagratings: Beyond the Limits of Graded Metasurfaces for Wave Front Control

Younes Ra'Di, Dimitrios L. Sounas, Andrea Alù

Research output: Contribution to journalArticlepeer-review

395 Scopus citations


Graded metasurfaces exploit the local momentum imparted by an impedance gradient to mold the impinging wave front. This approach suffers from fundamental limits on the overall conversion efficiency, and it is challenged by fabrication limitations on the spatial resolution. Here, we introduce the concept of metagratings, formed by periodic arrays of carefully tailored bianisotropic inclusions and show that they enable wave front engineering with unitary efficiency and significantly lower fabrication demands. We employ this concept to design reflective metasurfaces for wave front steering without limitations on efficiency. A similar approach can be extended to transmitted beams and arbitrary wave front transformation, opening opportunities for highly efficient metasurfaces for extreme wave manipulation.

Original languageEnglish (US)
Article number067404
JournalPhysical Review Letters
Issue number6
StatePublished - Aug 10 2017
Externally publishedYes

ASJC Scopus subject areas

  • General Physics and Astronomy


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