Metallic bowtie antenna for an ultrahigh plasmonic-based improvement of Raman scattering process

A plasmonic substrate has been suggested as a powerful spectroscopic amplifier to significantly enhance the scattered signal intensity in the Hyper-Raman Scattering (HRS) by exploiting the electromagnetic enhancement effect linked to plasmon excitation in coupled metallic resonators. The proposed dimer configurations include two equilateral nanotriangles of Au material, arranged in an Edge-to-Edge (EE) configuration and illuminated by longitudinally polarized light. For the selected two-particle system, the Finite-Difference Time-Domain (FDTD) electrodynamic simulation tool is employed to systematically investigate the impact of the structural parameters and intrinsic arrangements on the spectral response, nearfield coupling mechanism, and enhancement factor of HRS. Through precise adjustments to the structural characteristics and the internal configuration of the illuminated homodimer, the scattering signal of the HRS process can be increased to an unprecedentedly high value of 10 × 10²³. This limit can be further enhanced exponentially by increasing the side length of the coupled resonators.