Anisotropy and Bianisotropy

Abstract

AbstractThe electromagnetic properties of an isotropic medium are the same in all directions. Accordingly, isotropic media are characterized simply by scalar constitutive parameters that relate the induction field phasorsandto the primitive field phasorsand. In contrast, anisotropic media exhibit directionally dependent electromagnetic properties, such thatis not aligned withand/oris not aligned with. Furthermore, recent advances have focused attention on bianisotropic media wherein bothandare anisotropically coupled to bothand. Therefore, dyadics (i.e., second‐rank Cartesian tensors) are needed to relate the primitive and the induction field phasors in both anisotropic and bianisotropic media. Correspondingly, these media exhibit a vastly more diverse range of phenomena than do isotropic media. A consequence of this wealth of interesting properties is that electromagnetic analyses are considerably more complicated for anisotropic and bianisotropic media than for isotropic media. In this article, anisotropic and bianisotropic media are discussed in terms of their constitutive dyadics and spacetime symmetries. Planewave propagation, dyadic Green functions, and the conceptualization of anisotropic and bianisotropic media via homogenization are described. A brief account of anisotropic and bianisotropic behavior in nonlinear media concludes this article.