Tunable surface plasmon properties of hollow cylindrical nanocomposite structures

Hollow nanostructures are currently a typical topological structure in plasmonic optics and exhibit excellent surface plasmon resonance control capabilities. This article presents a composite structure model of a hollow cylindrical gold nanoparticle and a gold film. The absorption spectrum is calculated using the finite-difference time-domain (FDTD) method. Results indicate that this hollow nano-composite structure exhibits excellent plasmonic resonance and electromagnetic field enhancement effects. The impact of cavity structural parameters on the plasmonic optics of the composite structure is explored, highlighting the influence of inner and outer cavity diameters on the coupling of surface plasmon fields. By introducing symmetry breaking to achieve ultra-sensitive control over the optical properties of the structure, variations in cavity parameters result in more complex coupling effects. The asymmetric hollow nanostructure enhances plasmonic field intensity, allowing precise modulation of resonance peaks and significantly increasing electric field enhancement. This research demonstrates the potential for systematically adjusting cavity parameters and symmetry to achieve precise modulation of plasmonic resonance modes in optical device design and optimization.