Eigen Waves of a Plane Symmetric Anisotropic Waveguide

Precise dispersion equations for a plane symmetric dielectric anisotropic waveguide are obtained, in which the waveguide layer is isotropic, and the framing media are assumed to be anisotropic uniaxial media. The tensors of the dielectric permittivity of the framing media are not assumed to be diagonal, namely, in one of them this tensor is formed by rotating the diagonal tensor by some angle between the optical axis of the anisotropic medium and the direction of propagation of the electromagnetic wave. The tensor of dielectric permittivity of another anisotropic medium is rotated by the same angle, but in the opposite direction, with the optical axes of both framing media lying in a plane parallel to the boundaries of the waveguiding structure. Thus, in framing media, the existence of six-component electromagnetic waves is maintained. In the dispersion properties of such a waveguide, certain features are observed in comparison with the case when the framing media are assumed to be isotropic. It is found that the first symmetric mode of such a waveguide has a finite deceleration with zero thickness of the isotropic layer, which indicates the possibility of the appearance of surface electromagnetic waves (the so-called Dyakonov waves) at the boundaries of this isotropic layer. It is noted that the transition of the antisymmetric mode to the Dyakonov wave occurs with a finite thickness of the waveguiding layer. Dependencies of the deceleration of the elementary (symmetric) mode on the angle of rotation of the optical axis of anisotropic media relative to the direction of propagation of the guided wave of the waveguide structure are given.