Surface-Enhanced Raman Scattering on Silver Sinusoidal Nanograting: Impact of Interactions of Grating-Coupled Surface Plasmon Polaritons

In this study, we reported a silver sinusoidal nanograting used in microchannels, forming H2O/Ag/NOA/SiO2 heterostructure and studied the impact of interactions grating-coupled surface plasmon polaritons (SPPs) on surface-enhanced Raman scattering (SERS). There are two modes $$E_{x} (z)$$ Ag grating, namely, anti-symmetric mode (AM) at high SPP resonance frequency symmetric (SM) low-SPP frequency. When refractive indices upper lower dielectrics thin grating close, there will be strong coupling between SPPs interfaces, which increase transmittance but reduce maximum electromagnetic (EM) SERS substrate. Additionally, thinner stronger coupling, accompanied by shift modes. Our experimental results supported FDTD calculations, have corroborated importance design