Abstract
Abstract
In an asymmetric Au cubic trimer, influence of the rotation angle (θ) and side length (w) on both plasmonic coupling features and corresponding enhancement factor of hyper-Raman scattering (HRS) process have been investigated comprehensively under the illumination of a longitudinally polarized light. The finite-difference time-domain (FDTD) electrodynamic simulation tool has been employed to calculate the optical cross-section and associated nearfield intensity of the irradiated coupled resonators. As θ increases, the polarization state that dominates the coupling phenomenon is gradually switched from facing sides into facing edges which results in (1) a dramatic change in the spectral response of the trimer and (2) a significant improvement in the nearfield intensity that is directly related to the improvement of HRS signal. Breaking size symmetry of the cubic trimer provides a novel approach to reach the desired spectral response that permits such trimer to be used as an active substrate for HRS procedures. After optimizing both the orientation angle and size of the interacting plasmonic characters forming of the trimer, the enhancement factor of HRS process can reach a value never reported before as high as 1 × 1021.
Subject
Electrical and Electronic Engineering,Mechanical Engineering,Mechanics of Materials,General Materials Science,General Chemistry,Bioengineering
Reference35 articles.
1. Localized surface plasmon resonance sensors;Mayer;Chem. Rev.,2011
2. Theoretical study of optical properties of metallic ellipsoidal nanoparticles by discreet dipole approximation;Alsawafta;J. Nanomater.,2011
3. Simulated optical properties of gold nanocubes and nanobars by discrete dipole approximation;Alsawafta;J. Nanomater.,2011
4. Investigation of the validity of the universal scaling law on linear chains of silver nanoparticles;Alsawafta;J. Nanomater.,2014
5. Effect of non-alignment on nearfield coupling, charge density and sensitivity to the host medium of a gold nanorod homodimer;Alsawafta;J. Mater. Sci.,2022