Eksimers

Eksimers, also known as excimers, are transient, diatomic molecules that exist only in an electronically excited state. Upon relaxation to a lower energy state, they rapidly dissociate. This unique characteristic stems from the fact that their ground state is typically unbound or weakly bound, while their excited state is strongly bound.

The term "eksimer" is derived from "excited dimer," reflecting their diatomic nature and excited electronic configuration. These molecules are commonly formed when an electric discharge passes through a gas mixture, such as noble gases and reactive halogens or other electronegative species. The discharge excites the atoms, which can then form temporary eksimer molecules.

Eksimers are of significant interest in the field of lasers, particularly in excimer lasers. These lasers utilize the rapid dissociation of eksimer molecules to produce intense, short pulses of ultraviolet radiation. The excimer laser medium is typically composed of a noble gas and a halogen, like argon fluoride (ArF), krypton fluoride (KrF), or xenon chloride (XeCl). When excited by an electrical discharge, these components form eksimers, which then lase as they dissociate.

The properties of eksimer lasers, such as their high power output and short wavelength, make them valuable tools in various applications, including semiconductor manufacturing (photolithography), medical procedures (LASIK eye surgery), and materials processing. The transient nature of eksimers is crucial for their function as a gain medium, allowing for efficient energy storage and rapid pulse generation.