In the present paper, we show that it is possible to use a periodic structure of disconnected elements (e.g. a line of rods) to guide electromagnetic waves, in the direction of the periodicity. To study such segmented waveguides, we use the concept of quasimodes associated to complex frequencies. The numerical determination of quasimodes is based on a… (More)
This paper presents the Perfectly Matched Layers (PMLs) in the framework of transformation optics as a complex-valued change of coordinates. PMLs provide the suitable operator extensions required for the quasi-mode analysis of open problems. Leaky modes in open dielectric waveguides and spectral analysis of diffraction gratings are considered here.