Plasmonic Lattice Modes with High Quality Factor in Inhomogeneous Environment

Abstract

Plasmonic lattice modes (PLM) with high quality factor is formed by periodic Au hemisphere arrays on the quartz substrates. The formation of PLM is attributed to the coupling between the localized surface plasmon resonance of Au hemispheres and the diffracted waves inside the substrates rather than the diffracted waves in the air. By changing the hemispheres’ size and the arrays’ period, the PLM wavelength is adjustable. It is also found that the refractive index of the substrates has no effect on the quality factor of PLM. As the refractive index increases, the position of the PLM wavelength has a redshift. While the surroundings where periodic Au hemisphere arrays on the quartz substrates are located affect the quality factor of PLM.