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Graphene can support surface plasmons with higher confinement, lower propagation loss, and substantially more tunable response compared to usual metal-based plasmonic structures. Interestingly, plasmons in graphene can strongly couple with nanostructures and gratings placed in its vicinity to form new hybrid systems that can provide a platform to investigate more complicated plasmonic phenomena. In this Perspective, an analysis on the excitation of highly confined graphene plasmons and their strong coupling with metallic or dielectric gratings is performed. We emphasize the flexibility in the efficient control of light–matter interaction by these new hybrid systems, benefiting from the interplay between graphene plasmons and other external resonant modes. The hybrid graphene-plasmon grating systems offer unique tunable plasmonic resonances with enhanced field distributions. They exhibit a novel route to realize practical emerging applications, including nonreciprocal devices, plasmonic switches, perfect absorbers, nonlinear structures, photodetectors, and optical sensors.
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Comparative Analysis of the Near‐ and Far‐Field Optical Response of Thin Plasmonic Nanostructures
Abstract Nanostructures made of metallic materials support collective oscillations of their conduction electrons, commonly known as surface plasmons. These modes, whose characteristics are determined by the material and morphology of the nanostructure, couple strongly to light and confine it into subwavelength volumes. Of particular interest are metallic nanostructures for which the size along one dimension approaches the nanometer or even the subnanometer scale, since such morphologies can lead to stronger light–matter interactions and higher degrees of confinement than regular three‐dimensional nanostructures. Here, the plasmonic response of metallic nanodisks of varying thicknesses and aspect ratios is investigated under far‐ and near‐field excitation conditions. It is found that, for far‐field excitation, the strength of the plasmonic response of the nanodisk increases with its thickness, as expected from the increase in the number of conduction electrons in the system. However, for near‐field excitation, the plasmonic response becomes stronger as the thickness of the nanodisk is reduced. This behavior is attributed to the higher efficiency with which a near‐field source couples to the plasmons supported by thinner nanodisks. The results of this work advance the understanding of the plasmonic response of thin metallic nanostructures, thus increasing their potential for the development of novel applications.
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- Award ID(s):
- 1941680
- PAR ID:
- 10446107
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Optical Materials
- Volume:
- 10
- Issue:
- 9
- ISSN:
- 2195-1071
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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