Question

Why are birefringence materials so rare?

Answer 1

Explanation:

Birefringence is the optical property of a material having a refractive index that depends on the polarization and propagation direction of light.

Answer 2

Answer:

Birefringence occurs when you have different bonding forces in different directions in the crystal. These different bonding forces lead to a different refractive index in each direction. In amorphous materials, there is not a preferred direction or crystal structure. Bonding forces are the same for every direction and this causes the material to have a single refractive index.