Biprism
The biprism is a special prism that has two surfaces at the front that are at an obtuse angle (<180 °) to each other. The remaining areas are usually uninteresting for its use.
use
Augustin Jean Fresnel used the biprism for one of his interference experiments : Divergent light shines on the surface of the biprism and is refracted. Interference can now be observed on a screen or similar set up behind it . To z. B. to find out the wavelength of the light, one extends the marginal rays to the coherence gap. So everything can be calculated exactly as with the double slit test . A liquid is usually filled into the biprism in order to increase the refraction of light and to make the interference that occurs more clearly.
Web links
- Experiment setup and evaluation at student level ( LEIFI )