Polychromatic light

A polychromatic light is made up of a whole of Lumière S Monochromatique S, i.e. of a whole of electromagnetic waves of different wavelengths. The human eye associating with each wavelength visible a color, the etymological translation of the term is light containing several colors . Nevertheless the polychromatic term is extended to any type of radiation including those invisible by the man. By opposition a light not satisfying that a wavelength is known as monochromatic.

It will be noticed that in any rigor a light is never perfectly monochromatic, and that only the study of sound spectrum makes it possible to establish criteria distinguishing the monochromatic lights from the polychromatic ones. It is also possible to treat (or '' to filter '') a polychromatic light by a Monochromateur for example in order to select a given wavelength and to obtain a monochromatic Lumière.

Various types of polychromatic lights

One distinguishes mainly three types of polychromatic lights, according to their spectrum:

lights with discrete spectrum: they consist of a unit limited of well defined wavelengths radiations. the independent sources are the gas-discharge lamps (lamp with mercury, public lighting with sodium).
lights with continuous spectrum: they consist of one or more continuous intervals wavelengths. The independent sources are the emitting bodies of the light under the effect of heat (traditional Lamp incandescent, Sun).
lights with mixed spectrum: they are the superposition of the two preceding ones.

Random links: