Electromagnetic Fields of Hertzian Dipoles in Layered Negative Refractive Index Materials

The electromagnetic fields of a Hertzian dipole in layered negative refractive index material (NIM) are efficiently calculated using the fast all modes method (FAM) combined with the numerical modified steepest-descent path method (NMSP). The exact locations of all surface wave modes and all leaky wave modes are found for various NIM slab thicknesses. Both lossless and lossy cases are studied. It is observed that there are different types of surface wave modes or even no surface wave mode at certain slab thicknesses. The electromagnetic fields vary significantly when modes are excited or disappear at certain thicknesses.