Figure 2. Anisotropy and chirality.

(a) Materials that have preferred directions are anisotropic and can show linear birefringence and dichroism. (b) Molecules that cannot be superimposed with their mirror image have intrinsic 3D chirality and their solution can show optical activity³². (c) 3D chirality is also present and can also lead to circular birefringence and dichroism when the experimental arrangement consisting of material and direction of incidence k cannot be superimposed with its mirror image¹¹,¹².