Dual Channels of Transmission Using Rectangular Hole Dimers

Abstract

The optical properties of a plasmonic surface have been engineered using the rectangular nanohole dimers. One or two transmission peak(s), associated with two symmetrical or asymmetrical transmission channels, has (have) been revealed. We found that, similar to the plasmon coupling of a nanorod dimer, a strong coupling effect is also present in a rectangular nanohole dimer. The effect is closely correlated with the surrounding currents of waveguide modes, which mediate, via the magnetic field, an attractive or repulsive interaction between the dimer holes. The resulted low-energy or high-energy mode will couple with the film surface waves, thus producing the transmission peak with a red- or blue-shift. Moreover, the dependence of coupling modes on the sizes and separation of dimer holes has been systematically investigated, and an anticrossing-like coupling behavior has been suggested. We also suggest that, using the rectangular hole dimers with the perpendicular arrangement, the polarization of light can...