Polarization-controlled asymmetric excitation of surface plasmons

Abstract
Free-space light can be coupled into propagating surface waves at a metal–dielectric interface, known as surface plasmons (SPs). This process has traditionally faced challenges in preserving the incident polarization information and controlling the directionality of the excited SPs. The recently reported polarization-controlled asymmetric excitation of SPs in metasurfaces has attracted much attention for its promise in developing innovative plasmonic devices. However, the unit elements in these works were purposely designed in certain orthogonal polarizations, i.e., linear or circular polarizations, resulting in limited two-level polarization controllability. Here, we introduce a coupled-mode theory to overcome this limit. We demonstrated theoretically and experimentally that, by utilizing the coupling effect between a pair of split-ring-shaped slit resonators, exotic asymmetric excitation of SPs can be obtained under the x-, y-, left-handed circular, and right-handed circular polarization incidences, while the polarization information of the incident light can be preserved in the excited SPs. The versatility of the presented design scheme would offer opportunities for polarization sensing and polarization-controlled plasmonic devices.

Citation
Xu Q, Zhang X, Yang Q, Tian C, Xu Y, et al. (2017) Polarization-controlled asymmetric excitation of surface plasmons. Optica 4: 1044. Available: http://dx.doi.org/10.1364/OPTICA.4.001044.

Acknowledgements
National Key Basic Research Program of China (2014CB339800); National Natural Science Foundation of China (NSFC) (61420106006, 61422509, 61427814, 61605143); Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT) (IRT13033); National Science Foundation (NSF) (ECCS-1232081). Acknowledgment. We thank Veronic E. Tremblay for her advice on optimizing the writing.

Publisher
The Optical Society

Journal
Optica

DOI
10.1364/OPTICA.4.001044

Additional Links
https://www.osapublishing.org/optica/abstract.cfm?uri=optica-4-9-1044
https://doi.org/10.1364/optica.4.001044

Relations
Is Supplemented By:

Permanent link to this record