ABSTRACT
This chapter discusses peculiarities of electromagnetic fields in bounded media. It considers electromagnetic fields in generally inhomogeneous media. The chapter demonstrates how boundaries affect the wave excitation in homogeneous media and reviews eigen fields of bounded media with the main focus on piecewise homogeneous waveguides. Finding of eigenfields in bounded systems is generally more complicated than finding them in unbounded bulk materials. It requires eigenfields to satisfy not only the bulk conditions (the Maxwell's equations with zero external currents), but also the boundary conditions given by the medium's shape and adjacent materials. As a result, eigenfields of bounded media become dependent on the geometry and composition of the whole structure. Physically, the fields reflected by an interface correspond to the outgoing bulk eigenwaves of the external medium. Thus, the total solution in the external medium is generally given by the coupled incoming and outgoing bulk eigenwaves.
