Mirror-on-mirror platforms based on arrays of metallic nanoparticles,arranged top-down or self-assembled on a thin metallic film, haveinteresting optical properties. Interaction of localizedsurface-plasmons in nanoparticles with propagating surface-plasmons inthe film underpins the exotic features of such platforms. Here, wepresent a comprehensive theoretical framework which emulates such asystem using a five-layer-stack model and calculate its reflectance,transmittance, and absorbance spectra. The theory rests on dipolarquasi-static approximations incorporating image-forces and effectivemedium theory. Systematically tested against full-wave simulations, thissimple approach proves to be adequate within its obvious applicabilitylimits. It is used to study optical signals as a function ofnanoparticle dimensions, interparticle separation, metal film thickness,the gap between the film and nanoparticles, and incident lightcharacteristics. Several peculiar features are found, e.g., quenching ofreflectivity in certain frequency domains or shift of the reflectivityspectra. Schemes are proposed to tailor those as functions of thementioned parameters. Calculating the systems optical responses inseconds, as compared to much longer running simulations, this theoryhelps to momentarily unravel the role of each system parameter in lightreflection, transmission, and absorption, facilitating thereby thedesign and optimisation of novel mirror-on-mirror systems.

http://dx.doi.org/10.1039/C6CP04551K

D. Sikdar, S. B. Hasan, M. Urbakh, J. B. Edel, A. A. Kornyshev

2016

07/2016

Phys. Chem. Chem. Phys.

18

20486-20498

The Royal Society of Chemistry

plasmonics