Infra-Red Radiation

The region of the electromagnetic spectrum adjacent to that of visible light, but with longer wavelengths. Infra-red radiation is emitted by hot objects and by excited molecules. It is produced by the movement of charges on the molecular scale, by vibrational or rotational motion of molecules.

Covering wavelengths from 0.75x10^-6m to 1000x10^-6m it is normally grouped into near, intermediate and far infra-red regions.

Near Infra-Red

0.75 to 1.5x10^-6m

Intermediate Infra-Red

1.5 to 20x10^-6m

Far Infra-Red

20 to 1000x10^-6m

See also: Thermal Imaging Camera, Thermography, Ultraviolet Light, Visible Light.