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arXiv · 1502.05181

Observation of a surface lattice resonance in a fractal arrangement of gold nanoparticles

Ting Lee Chen·Jord C. Prangsma·Frans B. Segerink·Dirk Jan Dikken·Jennifer L. Herek
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Abstract

The collective response of closely spaced metal particles in non-periodic arrangements has the potential to provide a beneficial angular and frequency dependence in sensing applications. In this paper, we investigate the optical response of a Sierpinski fractal arrangement of gold nanoparticles and show that it supports a collective resonance similar to the surface lattice resonances that exist in periodic arrangements of plasmonic resonators. Using back focal plane microscopy, we observe the leakage of radiation out of a surface lattice resonance that is efficiently excited when the wavenumber of the incident light matches a strong Fourier component of the fractal structure. The efficient coupling between localized surface plasmons leads to a collective resonance and a Fano-like feature in the scattering spectrum. Our experimental observations are supported by numerical simulations based on the coupled-dipole approximation and finite-difference time-domain methods. This work presents a first step towards the application of fractal arrangements for plasmonic applications

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Ting Lee Chen, Jord C. Prangsma, Frans B. Segerink, Dirk Jan Dikken, Jennifer L. Herek. 2015-02-18. Observation of a surface lattice resonance in a fractal arrangement of gold nanoparticles. https://arxiv.org/abs/1502.05181

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