Doppelbrechende

Doppelbrechende, also known as double refraction, is an optical phenomenon where a single ray of light entering a birefringent material is split into two rays that travel at different speeds and in different directions. This effect is a result of the material's anisotropic nature, meaning it has different optical properties in different directions. The two rays are known as the ordinary ray and the extraordinary ray. The ordinary ray travels through the material as it would in an isotropic material, while the extraordinary ray travels at a different speed and direction due to the material's internal structure. This phenomenon is commonly observed in calcite and other birefringent crystals. Doppelbrechende has various applications in optics, such as in the design of polarizing filters and in the study of crystal structures. It is also responsible for the double image seen when looking through a calcite crystal, a phenomenon known as the "double image effect."