Dielectric Waveguides and Light-Guides

Abstract

Dielectric waveguides and lightguides occupy a great part of modern electrodynamics. The plane dielectric waveguide (Sect. 9.1) is the simplest representative of them. First wave investigations in such structures (the Goubau line type) are linked with the names Zenneck and Sommerfeld. A field in a layer satisfies the Helmholtz equation and the general boundary conditions (Sect. 2.1.2). Electrical and magnetic waves are examined with the help of the Hertz longitudinal vector. We obtain the transcendent dispersion equations for even and odd waves, which require a numerical solution. In particular, we note that the even electric surface wave E₀₀ in the layer has zero critical frequency (the Katsenelenbaum effect). Many examples of the field component behavior in the layer and in the surrounding space are given. Using Programs P.9.1, P.9.2, the reader may be acquainted with field pictures of the plane dielectric waveguide.