Birefringence analysis produces two classes of results.
Refractive index results show the change (from the nominal value) of the refractive index as a result of part stresses. These results are computed using a stress result (either at the end of packing or after warpage) and the optical properties of the material.
Phase difference and retardation results show the difference between horizontally-polarized and vertically-polarized light as it passes through the part from the specified direction. This difference can be expressed as an absolute distance (phase difference) or as a fraction of wavelength (retardation).
All Birefringence results require a 3D Warp analysis.