Analysis and approximate solutions of the dispersion equation of surface electromagnetic waves in insulator-metal-insulator structures

The article gives a mathematical analysis of the dispersion equation for surface electromagnetic waves (SEWs) in an insulator-metal-insulator (IMI) structure. Approximate formulas are obtained that enable one to calculate the wavenumbers of long-range and short-range SEWs propagating in symmetric and asymmetric planar IMI structures. The domain of existence of long-range SEWs has been established.