ABSTRACT
The macroscopic properties of an isotropic medium do not depend on the direction along which they are measured. In an anisotropic medium, there are specific directions that are associated with the structure of medium or with an external electric and/or magnetic field. Anisotropy is connected with the presence in space of specific directions (which are known as axes of symmetry) that are due to the arrangement of atoms or molecules (in natural crystals) or to structural elements. This chapter discusses the structure of a plane wave in an anisotropic medium and the refraction of the plane wave on the surface of positive crystal. It distinguishes three types of liquid crystals (LCs), namley, nematic LCs, smectic LCs, and cholesteric LCs. The chapter also includes exercise problems related to electromagnetic waves in anisotropic and optically active media.
