Fano resonance in two-intersecting nanorings: Multiple layers of plasmon hybridizations

We theoretically investigate the optical properties of two-intersecting nanorings (TINR), which exhibit a pronounced Fano resonance in the near-infrared region. A multiple-layer plasmon hybridization model is proposed to explain the reasons and forming processes of the Fano resonance. The dependence of the Fano resonance on the intersecting distance is also demonstrated. Moreover, the presented two-intersecting nanorings are employed as a biosensor exhibiting a 3-fold improvement of the figure of merit than that of a single-ring biosensor with the same resonant wavelength. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3702884]