Numerical computation of complex image Green´s functions for multilayer dielectric media: near-field zone and the interface region

The paper is primarily concerned with the problems arising in connection with the complex image Green´s function computation in the near-field zone and over the interface in multilayer dielectric media. The numerical difficulties are investigated related to the cases where the source and observation points are located along an axis perpendicular to the lamination and the observation point is located on the interface between two dielectric media. Methods for resolving these difficulties when using complex image representations are presented. For near-field computation a range is determined within which the surface waves must not be extracted from the spectral representation. Over the interface plane, to obtain a more accurate result, the complex images should be placed in the medium identical to the unbounded region or the medium with a lower dielectric constant