Resonant enhancement of Raman scattering in metamaterials with hybrid electromagnetic and plasmonic resonances

Abstract

A tri-layer metamaterial perfect absorber of light, consisting of (Al/ZnS/Al) films with the top aluminium layer patterned as an array of circular disk nanoantennas, is investigated for resonantly enhancing Raman scattering from C-60 fullerene molecules deposited on the metamaterial. The metamaterial is designed to have resonant bands due to plasmonic and electromagnetic resonances at the Raman pump frequency (725 nm) as well as Stokes emission bands. The Raman scattering from C60 on the metamaterial with resonantly matched bands is measured to be enhanced by an order of magnitude more than from C60 on metamaterials with off-resonant absorption bands peaked at 1090 nm. The Raman pump is significantly enhanced due to the resonance with a propagating surface plasmon band, while the highly impedance matched electromagnetic resonance is expected to couple out the Raman emission efficiently.The nature and hybridization of the plasmonic and electromagnetic resonances to form compound resonances are investigated by numerical simulations.

Metamaterials and Metasurfaces for Sensor Applications

“…Also, among various types of MM, it is worthy to note that nanodisks have been used for SERS substrate [ 87 , 88 ]. This type of nanostructure has several advantages such as easy fabrication, polarization-independent property, and relatively simple control of parameters (its radius and thickness) (see Figure 3 a).…”

Nanostructure-free Metal–Dielectric Stacks for Raman Scattering Enhancement and Defect Identification in CVD-Grown Tungsten Disulfide (2H-WS2) Nanosheets

“…Raman scattering enhancement in planar or periodic dielectric structures depends on the medium’s dimensionality and available photon density states . The earlier studies predicted and experimentally verified the enhanced electric field strengths due to the high photon density of states and their influence on Raman scattering enhancement in photonic crystal structures. , Here, we carried out TMM calculations to understand the effects of Al 2 O 3 and WS 2 layers thickness and the respective electric field strengths on the Raman scattering enhancement. The TMM calculations performed with a plane wave incidence on the TMDC side and the refractive index values for the WS 2 , Al 2 O 3 , and Al layers are considered from Hsu et al, Boidin et al, and Rakić, respectively.…”

“…In the context of amplification of spontaneous emission and Raman scattering, metal–dielectric photonic crystal structures are studied as they are composite structures, consisting of both photonic modes and plasmonic resonances. − Previous studies on multilayer dielectric stacks in the optical notch filter design are helpful for a comprehensive incident angular range . These structures emphasize the use of appropriate geometry and dimensions for the enhancement of weakly scattering materials such as a few-layered TMDCs and interfaces.…”

A review: metamaterial sensors for material characterization

“…LSPR is collective oscillation of free electrons in between dielectric and metallic structures because of interaction of incident optical wave (Maier, 2007). Here, the size of structures or particles should be smaller than the wavelength of incident optical wave (Shioi et al , 2014; Guddala et al , 2016). As we know metamaterials are sub-wavelength structures, interaction of incident optical wave with metamaterial structure oscillates free electrons in between substrate and structures exhibiting LSPR.…”