Solution box: SOLBOX-20: Electromagnetic interactions with near-zero-index triangular prisms

With their exotic behaviors that can be useful in a plethora of applications, near-zero-index (NZI) materials have been topics of many recent studies in electromagnetics [1–11]. Specifically, by possessing refractive index values close to zero, such materials can be employed for electromagnetic tunneling, coupling, beam steering and splitting, to name a few [1–8]. Manipulations of electromagnetic waves become possible by NZI structures as they stretch the wavelength to infinity. For example, once electromagnetic waves enter an NZI object located in an ordinary medium (e.g., vacuum), they tend to leave the object in the directions perpendicular to the surface. By then shaping the NZI object, one can create directive beams in the desired angles, even using isotopic sources as the main excitations.