Behavior Research Institute
ul•tra•vi•o•let
Pronunciation: (ul"tru-vī'u-lit),
[key]
—adj.
1. beyond the violet in the spectrum, corresponding to light having
wavelengths shorter than 4000 angstrom units.
2. pertaining to, producing, or utilizing light having such wavelengths:
an ultraviolet lamp. Cf. infrared.
Scientists have divided the ultraviolet part of the spectrum into three regions: the near ultraviolet, the far ultraviolet, and the extreme ultraviolet. The three regions are distinguished by how energetic the ultraviolet radiation is, and by the "wavelength" of the ultraviolet light, which is related to energy.
The near ultraviolet, abbreviated NUV, is the light closest to optical or visible light. The extreme ultraviolet, abbreviated EUV, is the ultraviolet light closest to X-rays, and is the most energetic of the three types. The far ultraviolet, abbreviated FUV, lies between the near and extreme ultraviolet regions. It is the least explored of the three regions.
The name means "beyond violet" (from Latin ultra, "beyond"), violet being the color of the shortest wavelengths of visible light. The color violet has the shortest wavelength in the visible spectrum. UV light has a shorter wavelength than that of violet light.