Open AccessGap plasmon-based phase-amplitude metasurfaces: material constraints [Invited]
Author(s) -
Anders Pors,
Sergey I. Bozhevolnyi
Publication year - 2015
Publication title -
optical materials express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 66
ISSN - 2159-3930
DOI - 10.1364/ome.5.002448
Subject(s) - plasmon , materials science , optics , phase (matter) , surface plasmon , amplitude , optoelectronics , surface plasmon polariton , phase modulation , refractive index , physics , phase noise , quantum mechanics
Gap surface plasmon (GSP) based metasurfaces, consisting of a subwavelength thin dielectric spacer sandwiched between a metal film and an array of metal nanobricks, have in recent years attracted considerable attention due to the ease of fabrication and the possibility to control both the phase and amplitude of the reflected light. In this work, we numerically investigate the influence of metal properties on the performance of GSP-based metasurfaces, considering in detail (at the wavelength λ = 800 nm) the typical plasmonic metal - gold, the alternative plasmonic material -titanium nitride, and the ideal metal (i.e., perfect electric conductor). We demonstrate that the plasmonic properties of non-ideal metals, in addition to the possibility to engineer the amplitude of the reflected light, also lead to a wider range of reflection phase control for relatively small unit cell sizes of ∼ λ/3 as compared to the metasurfaces using the ideal metal. Moreover, titanium nitride is found to represent a viable alternative (to gold) material that promises less stringent requirements when designing amplitude and phase-gradient GSP-based metasurfaces.