Fabrication and measurement of vertical split-ring resonators for light manipulation and metasurface

In the past decade, a number of interesting designs have been proposed to generate artificial magnetism at optical frequencies using plasmonic metamaterials, but owing to the planar configurations of typically fabricated metamaterials, the magnetic response is mainly driven by the incident electric field. Here, we fabricated vertical split-ring resonators (VSRRs) which behave as magnetic metamolecules sensitive to both the incident electric and magnetic fields upon excitation with the stronger induced magnetic energy in comparison to that of planar SRRs. Indeed, the magnetic resonance plays a key factor in plasmon coupling in VSRRs that is totally different from common electric-based metamaterials. A couple of potential applications such as VSRR-based highly sensitive refractive-index sensor and metasurface for light manipulation in optical communication frequency will also be presented. Because the plasmon properties of VSRR are changed via the upright configuration rather than the one parallel to the substrate, it can be used for high area density integration of metal nanostructures and opto-electronic devices.