Abstract
Self-complementary metasurfaces have gained significant attention due to their unique frequency-independent transmission and reflection properties and the possibility of the polarization transformation of plane waves. In this paper, we focus on the near-field spectrum to investigate, both theoretically and experimentally, the properties of surface waves supported by anisotropic self-complementary metasurfaces. We show that as a consequence of the electromagnetic Babinet’s duality, such a structure is hyperbolic for any frequency. We demonstrate the possibility of switching the canalization direction of surface waves with ultimately flat phase fronts for 90° by a very small frequency shift, paving the way to the extreme tunability and surface-wave routing. We reveal the polarization degree of freedom inherent to plane waves by demonstrating the all-frequency TE-TM polarization degeneracy of the surface waves along two principal directions. The results obtained open a plethora of opportunities for practical applications, including flat polarization devices, optical data-processing systems, sensing, holography and antennas.
- Received 14 April 2020
- Revised 16 May 2021
- Accepted 15 June 2021
DOI:https://doi.org/10.1103/PhysRevX.11.031038
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.
Published by the American Physical Society
Physics Subject Headings (PhySH)
Popular Summary
The miniaturization and flattening of modern data transfer and processing technologies require tunable control over highly localized electromagnetic fields. One promising carrier of such a localized field is the surface plasmon polariton, a type of electromagnetic wave that travels along an interface between two materials or along 2D conducting structures such as graphene or metasurfaces. Despite great success over the last 20 years in controlling the dispersion and directivity of surface plasmons, researchers have yet to achieve the routing of surface waves on planar structures and efficient, highly directional, in-plane energy transfer from point to point. Besides, the coding and transformation of information transferred by the propagating localized signal needs polarization control, which has not been achieved for surface plasmon polaritons. Here, we explore a new platform that allows us to resolve these problems and to achieve simultaneous control over surface waves’ routing and polarization control.
We create a resonant anisotropic 2D periodic structure whose unit cell consists of two mutually inverted patterns: a dipole antenna and a slot in a metal sheet with the same shape. Because of this symmetry, the structure exhibits intriguing near-field properties: Namely, we investigate theoretically and experimentally localized energy transfer along an ultranarrow line and frequency-independent propagation of surface waves with hyperbolic dispersion and constant polarization.
We consider this work as a significant milestone toward the development of planar optical and photonic devices. We believe our results pave the way to novel applications such as surface-wave polarizers and demultiplexers.
