Helmholtz Green's function for scalar wave propagation through a nano-hole on a plasmonic layer

An integral equation formulation is presented for describing the scalar wave propagation through a nano-hole on a plasmonic layer in terms of scalar Green’s function for the associated Helmholtz problem. Taking the radius of the nano-hole to be the smallest length parameter of the system, we obtain an exact closed-form analytic solution of the integral equation for the scalar Green’s function for scalar wave propagation through the nano-hole and the dispersion relations for such a plasmonic layer.