Numerical Investigation on Multiple Resonant Modes of Double-Layer Plasmonic Grooves for Sensing Application

Abstract

A high-performance multi-resonance plasmonic sensor with double-layer metallic grooves is theoretically constructed by introducing a polymethyl methacrylate groove with a numerical simulation method. Multiple resonance wavelengths can be generated at the oblique incidence, and the number and feature of resonant mode for sensing detection is different for various incident angles. Specifically, at the incident angle of 30 • , the reflection spectrum exhibits two resonant dips, in which the dip at the wavelength of 1066 nm has an extremely narrow line width of~4.5 nm and high figure of merit of~111.11. As the incident angle increases, the electric dipole mode gradually weakens, but the surface plasmon resonance and cavity resonance mode are enhanced. Therefore, for an incident angle of 65 • , three resonance dips for sensing can be generated in the reflection spectrum to realize three-channel sensing measurement. These double-layer plasmonic grooves have potential in the development of advanced biochemical surface plasmon polariton measurements.

Dispersion Theory of Surface Plasmon Polaritons on Bilayer Graphene Metasurfaces

“…The dispersion characteristic change in GSP mode is more sensitive by changing graphene ribbon width compared to the variation in gap size for the given structure. This also suggests that changing graphene ribbon width is more effective for creating some gradient-index metadevices where the full phase coverage is needed, such as high-efficiency couplers, meta-lenses, and enhanced emitters [ 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 ]. The analytic dispersion expressions are very useful to analyze its propagating characteristic and can also be directly used to design some novel graphene devices where its principle is to heavily rely on software simulations [ 49 , 50 , 51 , 52 ].…”

“…The obtained concise dispersion equations with frequency-wave vector relation include some structural and material parameters and, thus, provide a simple yet useful tool to analyze the basic propagation properties of GSP mode on double-layer graphene metasurfaces in Figure 1 . Further, they can also be readily used to develop some novel functional devices [ 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 ] if the specific dispersion diagrams are calculated.…”

“…The dispersion expression and mode distribution are simple for the single graphene metasurface [ 44 , 47 ]. Very recently, some functional plasmonic devices have also been designed on double-layer graphene metasurfaces in [ 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 ]. Compared to single-layer graphene metasurface, a double-layer structure can provide more degrees of freedom to control GSPs and, thus, may be more advantageous than a single-layer structure [ 52 , 53 , 54 ].…”

Ultranarrow Linewidth Coupling Resonance in Flexible Plasmonic Nanopillar Array for Enhanced Biomolecule Detection

“…Metallic nanostructures‐based plasmon resonance enable the concentration and enhancement of light into nanoscale spatial regions, which have driven advances in numerous applications including nano laser, [ 1,2 ] surface‐enhanced Raman scattering (SERS) [ 3–6 ] and biosensing. [ 7–10 ] Benefitting from their extremely strong near‐field enhancement, plasmonic nanostructures are highly sensitive to the ambient or local refractive index (RI) around the surfaces. In addition, the simple excitation of plasmons in nanostructures eliminate the shortcomings of bulky prism‐coupling required by conventional surface plasmon resonance (SPR) sensors, and promote the development of compact biosensor with the advantages of multiplexing, high‐throughput and portable detection.…”

Theoretical Analysis of Terahertz Dielectric–Loaded Graphene Waveguide

“…THz dielectric waveguides could realize a low loss mode propagation; however, the modal fields are diffraction-limited. In contrast to dielectric waveguides, metallic waveguides could support the transverse magnetic (TM) surface plasmon (SP) mode [ 29 ], while in the THz range, the SP effects of metal are relatively weak [ 30 ], thus hindering the applications at a subwavelength scale.…”