Excimer lasers, also known as exciplex lasers, are a type of ultraviolet laser that are commonly used in the production of microelectronic devices, semiconductor-based integrated circuits or “chips,” eye surgery, and micromachining. Excimer lasers have been widely used in high-resolution photolithography machines since the 1960s, and are one of the critical technologies required for microelectronic chip manufacturing.
An excimer laser typically employs a noble gas (argon, krypton, or xenon) in conjunction with a reactive gas (fluorine or chlorine). Under the right conditions of electrical stimulation and high pressure, a pseudo-molecule known as an excimer (or, in the case of noble gas halides, exciplex) is formed, which can only exist in an energized state and can generate ultraviolet laser light.
Because an excimer molecule has a bound (associative) excited state but a repulsive (dissociative) ground state, laser action occurs. Noble gases, such as xenon and krypton, are extremely inert and rarely form chemical compounds. When excited (by electrical discharge or high-energy electron beams), they can form temporarily bound molecules with themselves (excimer) or with halogens such as fluorine and chlorine (exciplex). The excited compound can release its excess energy through spontaneous or stimulated emission, resulting in a strongly repulsive ground state molecule that dissociates back into two unbound atoms very quickly (on the order of a picosecond). This results in a population inversion.
An excimer laser’s wavelength is determined by the molecules used and is typically in the ultraviolet range of electromagnetic radiation:
Relative Excimer Wavelength Power
Ar2* 126 nm
Kr2* 146 nm
F2* 157 nm
Xe2* 172 & 175 nm
ArF 193 nm 60
222 nm 25 KrCl
KrF 248 nm 100
308 nm XeCl 50
XeF 351 nm 45
Excimer lasers are light pulse-emitting gas lasers that produce an excited dimer via an electric discharge of a gas mixture containing an inert gas and a halogen gas, resulting in a molecule ArF that exists only in the excited state and has a life time of the order of 20ns.
Excimer Laser Therapy is a laser beam that uses ultraviolet B (UVB) light to treat the affected areas of skin.Any area of the body can be treated, including the scalp.
This treatment is highly effective, safe and painless. The excimer laser treats only the affected areas of skin as opposed to a Phototherapy unit which treats all exposed skin. Treatment time is typically less than 10-15 minutes.