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Fabrication of Nanopillar-Based Split Ring Resonators for Displacement Current Mediated Resonances in Terahertz Metamaterials
Published on: March 23, 2017
Optical plasmonic resonances in split-ring resonator structures: an improved LC model
T D Corrigan1, P W Kolb, A B Sushkov
1Department of Physics, University of Maryland, College Park, MD 20742, USA. tdcorrigan@lps.umd.edu
Optics Express
|November 26, 2008
Summary
We studied how the plasmonic resonance of silver nano-structures changes with shape. Complex structures like split rings exhibit distinct resonant modes, explained by an improved LC model.
Area of Science:
- Plasmonics and Nanophotonics
- Computational Electromagnetics
Background:
- Noble metal nanostructures exhibit unique optical properties due to surface plasmon resonances.
- The electromagnetic response of nanostructures is highly dependent on their geometry and arrangement.
Purpose of the Study:
- To systematically investigate the plasmonic resonant behavior of silver nanostructures with increasing geometric complexity.
- To understand the origin and evolution of different plasmonic modes in rods, U-shapes, and split ring resonators.
- To develop an improved model for describing the lowest order plasmonic resonance.
Main Methods:
- Fabrication and optical characterization of silver nanostructures (rods, U-shapes, split rings).
- Numerical simulations (electromagnetic field and current density analysis).
- Theoretical modeling using an enhanced LC circuit model.
Main Results:
- Plasmonic resonance red shifts as nanostructure complexity increases from rods to U-shapes to split rings.
- A second resonance mode appears and intensifies with U-shape arm extension, and a third mode emerges in split rings.
- Electromagnetic field and current density simulations reveal distinct current paths for different resonance modes.
- Detailed analysis of the lowest order mode, considering skin depth effects, supports an improved LC model.
Conclusions:
- The geometric evolution of silver nanostructures leads to predictable shifts and the emergence of distinct plasmonic resonance modes.
- Electromagnetic simulations provide crucial insights into the current distribution responsible for these modes.
- An enhanced LC model effectively describes the lowest order plasmonic resonance in these nanostructures.
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