Surface-wave-assisted nonreciprocity in spatio-temporally modulated metasurfaces.


Journal Article

Emerging photonic functionalities are mostly governed by the fundamental principle of Lorentz reciprocity. Lifting the constraints imposed by this principle could circumvent deleterious effects that limit the performance of photonic systems. Most efforts to date have been limited to waveguide platforms. Here, we propose and experimentally demonstrate a spatio-temporally modulated metasurface capable of complete violation of Lorentz reciprocity by reflecting an incident beam into far-field radiation in forward scattering, but into near-field surface waves in reverse scattering. These observations are shown both in nonreciprocal beam steering and nonreciprocal focusing. We also demonstrate nonreciprocal behavior of propagative-only waves in the frequency- and momentum-domains, and simultaneously in both. We develop a generalized Bloch-Floquet theory which offers physical insights into Lorentz nonreciprocity for arbitrary spatial phase gradients, and its predictions are in excellent agreement with experiments. Our work opens exciting opportunities in applications where free-space nonreciprocal wave propagation is desired.

Full Text

Duke Authors

Cited Authors

  • Cardin, AE; Silva, SR; Vardeny, SR; Padilla, WJ; Saxena, A; Taylor, AJ; Kort-Kamp, WJM; Chen, H-T; Dalvit, DAR; Azad, AK

Published Date

  • March 19, 2020

Published In

Volume / Issue

  • 11 / 1

Start / End Page

  • 1469 -

PubMed ID

  • 32193393

Pubmed Central ID

  • 32193393

Electronic International Standard Serial Number (EISSN)

  • 2041-1723

International Standard Serial Number (ISSN)

  • 2041-1723

Digital Object Identifier (DOI)

  • 10.1038/s41467-020-15273-1


  • eng