Question #3147c

1 Answer
Mar 19, 2017

The longer the wavelength, the smaller the deviation.


The refractive index #n# is the ratio between the speed of light in vacuum and the speed of light in the medium that the prism is made of. This is different for every wavelength.
Apparently this ratio is smaller for longer wavelengths. I have not yet heard of a material in which this is the other way around.

The way the light is refracted differently from red to violet is a property of the material, and may differ greatly between one sort of glass and another. Some glasses have a low average refraction and a relatively great red-violet difference, with others it's the other way around. By combining lenses of these two glasses we are able to colour correct our photographic lenses.