Adjective anisotropic It is used in the field of physical to qualify the body or substance that, according to the direction in which it is analyzed, has different physical properties. An anisotropic element thus differs from one isotropic, whose physical properties are identical in all directions.

In anisotropes, the temperature, the elasticity and the conductivity, among other properties, change according to the direction in which they are examined. As long as a physical property is able to be represented through a tensor magnitude, it can show anisotropic behavior.

To know the symmetry who has a property, it resorts to mathematical groups. In this way, a subgroup that is part of a rotational symmetry group allows characterizing the class of anisotropy that a certain property has.

If the property it does not vary under the influence of the group of rotations in three-dimensional space, it does not have anisotropy. On the contrary, it can be said that it presents isotropy.

Anisotropy is usually examined in the field of optics. When there is an anisotropic medium, changes are recorded in the refractive indices: light, in this framework, is transmitted at different speeds depending on the directions considered. So there is a range of refractive indices.

The anisotropic medium, on the other hand, produces a double refraction. This is because the light with incidence perpendicular to the surface, it is divided into two rays, which move through the medium with different paths and different speeds.