Chromatic dispersion refers to the way that light, under certain conditions, separates into its component wavelengths and the colours corresponding with each wavelength become visible to a human observer.
- Chromatic dispersion means dispersion according to colour.
- Chromatic dispersion is the result of the relationship between wavelength and refractive index.
- When light propagates from one medium (such as air) to another (such as water or glass) every wavelength is affected to a different degree according to the refractive index of the media concerned. There result is that each wavelength changes direction and speed. In the case of a light source producing white light, the separate wavelengths fan out with red at one extreme and violet at the other.
- A familiar example of chromatic dispersion is when white light strikes raindrops and a rainbow becomes visible to an observer.
- Remember that wavelength is a property of electromagnetic radiation, whilst colour is a feature of visual perception.