Lasers where optical amplification occurs in a plasma containing excited dimers with an anti-binding electronic Ground state.

An excimer Laser is a powerful kind of laser which is nearly always operated in the Ultraviolet spectral region and generates nanosecond pulses. The excimer Gain medium is a gas mixture, typically containing a noble gas and a halogen, apart from helium and/or neon as Buffer gas. An excimer gain medium is pumped with short current Pulses in a high-voltage electric discharge (or sometimes with an Electron beam), which create so-called excimers molecules which represent a bound state of their constituents only in the excited electronic state, but not in the electronic ground state.