Efficient computation of the 2D Green's function for 1D periodic layered structures using the Ewald method

An alternative direct procedure for applying the Ewald approach to obtain the Green's function for an array of line sources with 1D periodicity is presented. Furthermore, an algorithm for choosing the Ewald splitting parameter E that extends the efficiency of the method when the periodicity is somewhat larger than a wavelength is derived. In particular, the dyadic Green's function formalism is combined with the Ewald method