Nyström-Type Technique for Electromagnetic Wave Scattering in Inhomogeneous Material, Plasma and Metamaterial Slabs

We present a simple, stable, and spectrally-accurate quasi-analytical method for studying the reflection, transmission, and radiation of EM waves in the presence of single-layer or multilayer material, plasma, or metamaterial slabs that are inhomogeneous along the normal to the slab interfaces. Our approach formulates the problem as a linear Volterra integral equation of the second kind, discretized using an entire-domain Nyström method with a high-order Gauss-type quadrature. The proposed algorithms ensure mathematically guaranteed spectral convergence, handle electrically thin to electrically thick slabs, and can accommodate discontinuous inhomogeneity profiles. Application examples include one-dimensional band-gap structures, field enhancement in inhomogeneous metamaterial slabs with zero-crossings in permittivity, and dipole-driven plasma antennas.