Modulated terahertz responses of split ring resonators by nanometer thick liquid layers

The terahertz responses of planar arrays of split ring resonators with 50 nm thin liquid layers introduced in the interspaces between the metal structures have been studied using the terahertz-time domain spectroscopy technique. In our experimental configuration, both the circular current driven and linear polarization induced resonances show redshifted and enhanced transmission. The dielectric functions extracted from an effective medium model indicate that the behavior of the surface and interface charge oscillations is highly sensitive to the interface environment changes. The results suggest that this kind of device may be used for sensing applications. (C) 2008 American Institute of Physics.