Question

if an anisotropic material is placed between crossed polarizers, what should we observe? Why?

Answer 1

If we place an anisotrpic material is placed between crossed polarizers, often colours will appear. This happens because the linearly polarized light transmitted through a thin sheet of anisotropic material becomes elliptically polarized. The first parameter that defines the polarization state of transmitted light is the angle between the transmission direction of the polarizer and one of the principal axes of the anisotropic material. This angle defines the amplitudes of the electric field in both beams that the light spilts in an anisotropic material.