Open AccessExceptional point-based plasmonic metasurfaces for vortex beam generation
Author(s) -
Ho Ming Dick Leung,
Wensheng Gao,
Ranran Zhang,
Qi Zhao,
Xia Wang,
Che Ting Chan,
Jensen Li,
Wing Yim Tam
Publication year - 2020
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.28.000503
Subject(s) - plasmon , optics , optical vortex , polarization (electrochemistry) , holography , context (archaeology) , metamaterial , optoelectronics , physics , beam (structure) , paleontology , chemistry , biology
An exceptional point occurring in a tailor-made lossy optical system has been recently found to alter optical properties in counter-intuitive ways. In the context of tunable plasmonic devices, exceptional points can be useful as a driving mechanism to enhance tunability. Here, we experimentally demonstrate how a plasmonic exceptional point can be incorporated in metasurface Q-plates to have the generated vortex beam tuned through a change of structural parameter. We have observed an orbital rotation in the far-field by 45 degrees in crossing the exceptional point. We expect a new generation of tunable plasmonic devices in polarization control, beam structuring and holograms, which can take advantage of the huge sensitivity from exceptional points.