Greens function surface integral equation method for the electromagnetics of a single subwavelength groove in a metal surface

Abstract

A Greens function surface integral equation method for studying the electromagnetic properties of a single sub-wavelength groove in an otherwise flat metal surface is presented. It can be applied to calculate scattering, extinction and absorption cross sections, and particularly the excitation of surface plasmon polaritons propagating away from the groove along the metal surface. The method is exemplified for light with wavelength 1700 nm being normally incident on a 60 nm wide rectangular groove in a gold surface of varying depth, and it is demonstrated that for this example the scattering cross section at resonance can be app. 30 times the physical groove width. At the conference the method will be presented in further depth, including also a study of a broad range of grooves.