Birefringence analysis produces two classes of results.
Birefringence results are generated from the stress results produced by a 3D Warp analysis.
The refractive index of a transparent material is a dimensionless property which specifies the factor by which light slows down as it travels through the material. For most materials the refractive index is independent of the direction of travel and polarization of the light. However, stress can alter the refractive index of a material. If the stress is different in different directions then the material's refractive index may depend on the polarization of the incident light. This phenomenon is known as birefringence.
Birefringence simulations use a spectrum correction factor that modifies the influence of viscoelastic deformations on the birefringence results.