Glossary
- Anisotropic medium: medium in which the speed of a light wave and therefore the refraction index depend on the direction of propagation and on the polarization
- Birefringence: property of an anisotropic medium in which light propagates differently depending on its polarization
- Uniaxial material: said of a birefringent material for which the ordinary and extraordinary refraction indexes are identical for plane waves propagating in a given direction called the optical axis
- Optical axis ( birefringent material ): direction of propagation of a wave in a birefringent material for which the polarization remains unchanged
- Refraction index: for a transparent medium, ratio between the light speed in the air and the light speed in the medium ; for a reflective surface in the air or vacuum, the refraction index is « - 1 »
- Ordinary refraction index: in a birefringent uniaxial material, said of the refractive index seen by that of the two refracted rays from a single incident ray whose polarization is perpendicular to the optical axis
- Extraordinary refraction index: in a birefringent uniaxial material, said of the refractive index seen by that of the two refracted rays from a single incident ray whose polarization is not perpendicular to the optical axis