Actively controllable EIT-like resonance between localized and propagating surface plasmons for optical switching

摘要

We theoretically investigate the plasmonic interaction between radiative localized surface plasmon resonances and subradiative propagating surface plasmon modes in a nanostructure consisting of a periodic array of gold nanobars and an optically thick gold film, separated by a silica dielectric spacer layer. A controllable transparency window within the broad dipole resonance profile is observed clearly in the reflectance spectra via tailoring the length of the bar, the periodicity of the nanoparticle array, or the incident angle of applied field, respectively, a classic analog of electromagnetically induced transparency (EIT). We believe that the last excitation configuration is particularly beneficial for the realization of active manipulation of plasmonic optical switching without using coupling/control fields required in the conventional EIT scheme.