Optical field enhancement in gold Nanoplate assemblies

Abstract

Plasmons excited in noble metal nanoparticles squeeze light into a nanometer scale and enhance the optical field. The enhanced optical field is promising for chemical sensing and photochemical reactions. Optical field confinement is very intense at the junctions of the nanoparticle assemblies. In this study, we investigate the optical field enhancement of gold nanoplate assemblies via nonlinear optical microscopy. We found that the nonlinear signal increases with the size of the assembly and shows saturation behavior in the large assembly. The light confinement capability at the junction is evaluated, and the results indicate that the hexamer results in the most intense optical field.