Unified Theory of Surface-Plasmonic Enhancement and Extinction of Light Transmission through Metallic Nanoslit Arrays

Abstract

Metallic nanostructures are of immense scientific interest owing to unexpectedly strong interaction with light in deep subwavelength scales. Resonant excitations of surface and cavity plasmonic modes mediate strong light localization in nanoscale objects. Nevertheless, the role of surface plasmon-polaritons (SPP) in light transmission through a simple one-dimensional system with metallic nanoslits has been the subject of longstanding debates. Here, we propose a unified theory that consistently explains the controversial effects of SPPs in metallic nanoslit arrays. We show that the SPPs excited on the entrance and exit interfaces induce near-total internal reflection and abrupt phase change of the slit-guided mode. These fundamental effects quantitatively describe positive and negative effects of SPP excitation in a self-consistent manner. Importantly, the theory shows excellent agreement with rigorous numerical calculations while providing profound physical insight into the properties of nanoplasmonic systems.

Family of graphene-assisted resonant surface optical excitations for terahertz devices

“…A sharp resonance characterized by a transmittance maximum followed by a transmission minimum as shown in Fig. 2d is a characteristic feature of a Fano resonance supported by a metallic grating 17 . This Fano resonance is the result of the interference between the discrete metal SPP mode and the non-resonant continuum 18 .…”

“…2f . In this case, a spoof SPP mode is also called a cavity mode, which plays an important role in extraordinary optical transmission (EOT) 17 19 . Spoof SPP modes can also couple with graphene SPP modes to open up gaps in the dispersion curves, as indicated by the white arrows in Fig.…”

“…As the dispersion curve of the cavity modes approaches the resonance frequency of a metal SPP mode, the resultant spoof SPP mode becomes a mixed state of metal SPP and spoof SPP, with the field distribution in the gaps and also on the metal grating. The dispersion curves of two spoof SPPs, characterized by a high transmittance 17 , are shown in Fig. 3e .…”

Ultrahigh-Q metallic nanocavity resonances with externally-amplified intracavity feedback

“…According to our recent analysis 26 , surface plasmon-polaritons (SPP) at the entrance and exit interfaces cause interfacial Fano resonances that drastically modify τ and ρ in within their resonance bandwidth. The effects of the SPP-mediated interfacial Fano resonance include the antiresonant extinction of τ , i.e., τ → 0, and associated total internal reflection of the CM, i.e., | ρ in | → 1.…”

Nanophotonic identification of defects buried in three-dimensional NAND flash memory devices

“…Such properties include dispersion band engineering 1,2 , extraordinary optical transmission [3][4][5] , giant nonlinear effects 6,7 , enhanced cavity-quantum-electrodynamic coupling 8,9 and optical bound states in the radiation continuum 10,11 . There is now though a growing demand to turn academic research in the field into practical applications 12,13 , and a number of promising technologies are in development, including optical biochemical sensing 14,15 , thin-film photovoltaics 16 , nanolasers 17 and heat-assisted magnetic recording 18 .…”