dispersion

Definition: (1) Phenomenon of light in which degree to which beam of light is refracted or diffracted depends on its wavelength. * Dispersion can be by two mechanisms: (a) refraction: due to increase in refractive index as wavelength decreases; (b) diffraction: due to increase in diffractive effect as wavelength increases. * Dispersion of white light by refraction causes the splitting up of beam into its wavelength components i.e. a spectrum or rainbow of colours. * Also called chromatic dispersion. (2) Suspension or distribution of substance in liquid to form colloid or suspension. * Also called disperse phase.

Related Terms: Abbe constant

Previous Term: discrete spectrum  Next Term: D-line