Editing Halogen lamp (section)

==Spectrum==
[[File:Halogen spectrum.svg|thumb|Power of a halogen light as a function of wavelength. The colored band indicates the visible light spectrum.  Note that this spectrum is distorted by the [[responsivity]] of the [[photodiode|optical detector]] used in the measurement, greatly reducing the apparent power in the infrared.]]
Like all [[incandescent light bulb]]s, a halogen lamp produces a continuous spectrum of light, from near ultraviolet to deep into the infrared.<ref>[http://zeiss-campus.magnet.fsu.edu/articles/lightsources/tungstenhalogen.html Tungsten-halogen lamp information] {{webarchive|url=https://web.archive.org/web/20110303211343/http://zeiss-campus.magnet.fsu.edu/articles/lightsources/tungstenhalogen.html |date=2011-03-03 }} at Karl Zeiss Online Campus site (accessed Nov. 2 2010)</ref> Since the lamp filament can operate at a higher temperature than a non-halogen lamp, the spectrum is shifted toward blue, producing light with a higher effective [[color temperature]] and higher power efficiency. <!-- good full range spectrum line drawing needed -->

High-temperature filaments emit some energy in the [[ultraviolet|UV]] region. Small amounts of other elements can be mixed into the quartz, so that the ''doped'' quartz (or selective optical coating) blocks harmful UV radiation. Hard glass blocks UV and has been used extensively for the bulbs of car headlights.<ref>Burgin Lighting Research and Technology 1984 16. 2 71</ref> Alternatively, the halogen lamp can be mounted inside an outer bulb, similar to an ordinary incandescent lamp, which also reduces the risks from the high bulb temperature. Undoped quartz halogen lamps are used in some scientific, medical, and dental instruments as a UV-B source.