Vertical split-ring resonator based nanoplasmonic sensor

Split-ring resonators (SRRs) have been the subject of investigation as plasmonic sensors that operate by sensing plasmon resonance shift delta lambda when exposed to a medium with a refractive index change delta n. However, conventional planar SRRs have their plasmon fields spread into the substrates, reducing accessible sensing volume and its sensing performance. Such a limitation can be eradicated with vertical SRRs in which the plasmon fields localized in SRR gaps are lifted off from the substrate, allowing for greatly enhanced sensitivity. Here, we demonstrate the highest sensitivity among reported SRR-based sensors in optical frequencies. (c) 2014 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.