Dispersion is the phenomenon where different wavelengths of a wave travel at different speeds through a medium, causing them to spread out. In optics, this leads to the separation of white light into its constituent colors, as each color bends by a different amount when passing through a prism or lens. A medium having this common property may be termed a dispersive medium.

Within optics, dispersion is a property of telecommunication signals along transmission lines or the pulses of light in optical fiber.

In optics, one important and familiar consequence of dispersion is the change in the angle of refraction of different colors of light, as seen in the spectrum produced by a dispersive prism.

Written by Albert Marin