Plasmon–exciton induced transparency in plexcitonic Ag–CuCl-coated nanowires and associated arrays

Abstract

The plasmon–exciton couplings in Ag–CuCl-coated nanowires (ACNWs) have been investigated by using the scattering theory and the finite element method. It is found with increasing the shell thickness that the dipole plasmon resonance of the Ag nanowire can be tuned through the exciton resonance in the CuCl shell. The strong coupling between the plasmon resonance in the Ag nanowire and the exciton resonance in the CuCl shell leads to two new hybridized plexcitonic modes. The dispersion curves of the plexcitonic modes in the ACNWs are studied, and the obtained splitting energy is about 88 meV. We further find that the destructive interference between the plasmon and exciton resonances results in the plasmon–exciton induced transparency. As the TE wave propagates through the ACNW array, an extraordinary transmittance can be found in the ACNW array at the scattering dip of the ACNW.