Rapid Fire
Birefringence
- 21 Mar 2025
- 2 min read
Refraction is the bending of light as it passes from one medium to another due to a change in its speed. However, some materials also exhibit a phenomenon known as Birefringence (Double refraction).
Birefringence: It is the optical property of certain materials where incident light splits into 2 rays, each traveling at different speeds due to varying refractive indices in different directions. It arises due to the anisotropic nature of materials.
- The refractive index is the ratio of the speed of light in a vacuum to its speed in a medium. A vacuum has a refractive index of 1. A higher refractive index indicates greater optical density and slower light speed.
- Types of Birefringent Materials:
- Natural: Calcite, quartz, mica
- Synthetic: Barium borate, lithium niobate
- Induced: Can be created by applying physical stress, electric, or magnetic fields
- Applications: Used in LCDs, microscopes, optical switches, waveplates, frequency converters, and lasers for light manipulation.
Isotropic and Anisotropic Materials:
- Isotropic Materials: Have uniform structure, refract light at a constant angle, and allow it to pass at a single velocity without polarization. Eg: Glass, Table salt (NaCl).
- Anisotropic Materials: Have different crystal axes, causing light to split into 2 rays with different velocities and perpendicular polarization (birefringence). Eg: Calcite, Quartz, Mica, Tourmaline.
| Read More: Photonic Crystal |
