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Proceedings Paper

Robust surface-wave propagation and leaky-wave radiation based on three-dimensional topological plasmonic materials (Conference Presentation)
Author(s): Kunal Shastri; Francesco Monticone

Paper Abstract

Student Contribution: Magnetically-biased non-reciprocal plasmonic media may support Weyl points in their three-dimensional dispersion under certain conditions (for example if the cyclotron frequency exceed the plasma frequency). The projection of these Weyl points onto the two-dimensional surfaces of the plasmonic medium are connected by topologically-protected Fermi arc surface states. In this paper we show that the Fermi arc-based surface plasmon-polaritons can be engineered for three-dimensional topologically-robust, open wave-guiding and radiation. Specifically, in a nonreciprocal plasmonic block we demonstrate that: (a) The propagating surface modes are highly directional due to the hyperbolic dispersion of the Fermi arcs. (b) The modes appear outside the light-cone dispersion and consequently do not lose energy to radiation during guided-wave propagation. (c) The modes do not typically scatter into the bulk although there is no complete band gap in three dimensions due to the presence of Weyl points. (d) Appropriately designed coatings on the surface of the plasmonic block allow the surface modes to become highly-directive leaky modes with tunable radiation properties. (e) The presence of scattering and absorption losses in the plasma does not destroy the topological robustness of the propagating mode. We show that only very high anisotropic losses may lead to a topological transition. The topological protection, directive light propagation, and controllable coupling to radiation modes make this system an attractive platform for complex wave re-routing in three dimensions.

Paper Details

Date Published: 9 September 2019
Proc. SPIE 11081, Active Photonic Platforms XI, 1108107 (9 September 2019); doi: 10.1117/12.2529368
Show Author Affiliations
Kunal Shastri, Cornell Univ. (United States)
Francesco Monticone, Cornell Univ. (United States)

Published in SPIE Proceedings Vol. 11081:
Active Photonic Platforms XI
Ganapathi S. Subramania; Stavroula Foteinopoulou, Editor(s)

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