VUV / Excimer
VUV is an abbreviation of vacuum-ultraviolet, which describes wavelengths shorter than 200 nm. These wavelengths are strongly absorbed by the oxygen in the air. They have significance in, for example, optical cleaning processes.
The term excimer refers to a temporary atomic state in which high-energy atoms form short-lived molecular pairs, or dimers, when electronically excited. These pairs are called excited dimers. As the excited dimers return to their original state, the residual energy is released as a ultraviolet C (UV-C) photon. Excimer lamps are specially coated, noble gas-filled emitters which irradiate the desired wavelength, from 172 nm to 222 nm.
