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.
Topics in this section
- About Birefringence
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.