Spatio-spectral measurement of a surface plasmon polariton in a gold nano-slit array

Abstract

A spatio-spectral measurement of transmitted near field distribution from a nano optic structure is demonstrated by near field scanning optical miscroscopy (NSOM) with the point spectroscopic approach. This method provides spectral information of nano-optic system with sub-diffraction limit spatial resolution. The gold nano slit array is a good model system where analytical calculation is possible by the modal expansion method for all diffraction orders with surface impedance boundary conditions. The point spectroscopic analysis of near field distribution shows a good agreement with theoretical model calculation.