Effect of gap width on enhanced magnetic optical fields in metallic split ring resonators

Abstract

We analyze the U-shaped metallic split-ring resonators (SRRs) aimed at creating highly confined and enhanced magnetic field in the near-infrared frequency range. At the magnetic resonance, the induced circulating current of the SRRs could lead to a strong enhancement of the surrounding magnetic field. Such a magnetic field enhancement is found to be dominated by the gap width between two SRR arms. By decreasing the gap width to 10 nm, the SRR is predicted to have a 3790-fold enhancement of the magnetic field at the resonance wavelength of 1340 nm. © 2012 Copyright 2012 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License.