The excimer laser was invented in 1970 by Nikolai Basov, V. A. Danilychev and Yu. M. Popov, at the Lebedev Physical Institute in Moscow, using a xenon dimer (Xe2) excited by an electron beam to give stimulated emission at 172 nm wavelength. An excimer laser typically uses a combination of a noble gas and a reactive gas. Under the appropriate conditions of electrical stimulation and high pressure, a pseudo-molecule called an excimer is created, which can only exist in an energized state and can give rise to laser light in the ultraviolet range.