Local Field Enhancement Due to the Edge States of Nanoplasmonic Crystal

Abstract

In this paper, we describe the effect of local electric field enhancement due to the existence of photonic edge states in a nanoplasmonic crystal. These states can be excited by a normal incident wave and are localized along the continuous line defect, where translational symmetry is broken. The nanoplasmonic crystal is formed by a triangular lattice of SiO2 cylinders on top of SiO2 and Ag thin films. Numerical simulations demonstrated that edge modes that are concentrated around a defect in a nanophotonic crystal may result in 12 field enhancements of the electric field for the incident plane wave of wavelength 545 nm. This effect can be employed for improving the sensitivity of surface-enhanced Raman scattering (SERS) spectroscopy, increasing the Purcell factor of quantum systems and improving the efficiency of higher harmonic generation.

Keywords

• nanoplasmonic crystal
• photonic edge states
• local field enhancement